diff --git a/src/main/java/org/gcube/informationsystem/base/reference/AccessType.java b/src/main/java/org/gcube/informationsystem/base/reference/AccessType.java
index 15c4ce0..c7f3daa 100644
--- a/src/main/java/org/gcube/informationsystem/base/reference/AccessType.java
+++ b/src/main/java/org/gcube/informationsystem/base/reference/AccessType.java
@@ -17,7 +17,6 @@ import org.gcube.informationsystem.model.impl.entities.ResourceImpl;
 import org.gcube.informationsystem.model.impl.properties.DummyProperty;
 import org.gcube.informationsystem.model.impl.properties.PropertyImpl;
 import org.gcube.informationsystem.model.impl.relations.ConsistsOfImpl;
-import org.gcube.informationsystem.model.impl.relations.DummyConsistsOf;
 import org.gcube.informationsystem.model.impl.relations.DummyIsRelatedTo;
 import org.gcube.informationsystem.model.impl.relations.IsRelatedToImpl;
 import org.gcube.informationsystem.model.impl.relations.RelationImpl;
@@ -28,6 +27,14 @@ import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.model.reference.relations.ConsistsOf;
 import org.gcube.informationsystem.model.reference.relations.IsRelatedTo;
 import org.gcube.informationsystem.model.reference.relations.Relation;
+import org.gcube.informationsystem.types.impl.entities.EntityTypeDefinitionImpl;
+import org.gcube.informationsystem.types.impl.properties.PropertyDefinitionImpl;
+import org.gcube.informationsystem.types.impl.properties.PropertyTypeDefinitionImpl;
+import org.gcube.informationsystem.types.impl.relations.RelationTypeDefinitionImpl;
+import org.gcube.informationsystem.types.reference.entities.EntityTypeDefinition;
+import org.gcube.informationsystem.types.reference.properties.PropertyDefinition;
+import org.gcube.informationsystem.types.reference.properties.PropertyTypeDefiniton;
+import org.gcube.informationsystem.types.reference.relations.RelationTypeDefinition;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -38,18 +45,23 @@ import org.slf4j.LoggerFactory;
  */
 public enum AccessType {
 
+	PROPERTY_DEFINITION(PropertyDefinition.class, PropertyDefinition.NAME, PropertyDefinitionImpl.class, null),
+	PROPERTY_TYPE_DEFINITION(PropertyTypeDefiniton.class, PropertyTypeDefiniton.NAME, PropertyTypeDefinitionImpl.class, null),
 	PROPERTY(Property.class, Property.NAME, PropertyImpl.class, DummyProperty.class),
 	
 	CONTEXT(Context.class, Context.NAME, ContextImpl.class, null),
 	IS_PARENT_OF(IsParentOf.class, IsParentOf.NAME, IsParentOfImpl.class, null),
 	
+	ENTITY_TYPE_DEFINITION(EntityTypeDefinition.class, EntityTypeDefinition.NAME, EntityTypeDefinitionImpl.class, null),
+	RELATION_TYPE_DEFINITION(RelationTypeDefinition.class, RelationTypeDefinition.NAME, RelationTypeDefinitionImpl.class, null),
+		
 	ENTITY(Entity.class, Entity.NAME, EntityImpl.class, null),
 	RESOURCE(Resource.class, Resource.NAME, ResourceImpl.class, DummyResource.class),
 	FACET(Facet.class, Facet.NAME, FacetImpl.class, DummyFacet.class),
 		
 	RELATION(Relation.class, Relation.NAME, RelationImpl.class, null),
 	IS_RELATED_TO(IsRelatedTo.class, IsRelatedTo.NAME, IsRelatedToImpl.class, DummyIsRelatedTo.class),
-	CONSISTS_OF(ConsistsOf.class, ConsistsOf.NAME, ConsistsOfImpl.class, DummyConsistsOf.class);
+	CONSISTS_OF(ConsistsOf.class, ConsistsOf.NAME, ConsistsOfImpl.class, null);
 	
 	private static Logger logger = LoggerFactory.getLogger(AccessType.class);
 	
diff --git a/src/main/java/org/gcube/informationsystem/base/reference/entities/BaseEntity.java b/src/main/java/org/gcube/informationsystem/base/reference/entities/BaseEntity.java
index 2a410bf..24bb255 100644
--- a/src/main/java/org/gcube/informationsystem/base/reference/entities/BaseEntity.java
+++ b/src/main/java/org/gcube/informationsystem/base/reference/entities/BaseEntity.java
@@ -1,7 +1,9 @@
 package org.gcube.informationsystem.base.reference.entities;
 
 import org.gcube.informationsystem.base.reference.ER;
+import org.gcube.informationsystem.base.reference.properties.Header;
 import org.gcube.informationsystem.types.annotations.Abstract;
+import org.gcube.informationsystem.types.annotations.ISProperty;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 
@@ -11,5 +13,10 @@ import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 public interface BaseEntity extends ER {
 	
 	public static final String NAME = "BaseEntity"; //Entity.class.getSimpleName();
+
+	/* Overriding getHeader method to create Header property in type */
+	@ISProperty(name=HEADER_PROPERTY, mandatory=true, nullable=false)
+	@Override
+	public Header getHeader();
 	
 }
\ No newline at end of file
diff --git a/src/main/java/org/gcube/informationsystem/base/reference/properties/BaseProperty.java b/src/main/java/org/gcube/informationsystem/base/reference/properties/BaseProperty.java
index 0f9ab6d..ddc3c69 100644
--- a/src/main/java/org/gcube/informationsystem/base/reference/properties/BaseProperty.java
+++ b/src/main/java/org/gcube/informationsystem/base/reference/properties/BaseProperty.java
@@ -2,15 +2,12 @@ package org.gcube.informationsystem.base.reference.properties;
 
 import org.gcube.informationsystem.base.reference.ISManageable;
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-
 /**
  * @author Luca Frosini (ISTI - CNR)
  * Root Class for Property types. It creates a base common type, which is useful
  * for management purpose.
  */
-// @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = ISManageable.CLASS_PROPERTY)
-@JsonIgnoreProperties(ignoreUnknown=true)
+// @JsonDeserialize(as=BasePropertympl.class) Do not uncomment to manage subclasses
 public interface BaseProperty extends ISManageable {
 	
 	public static final String NAME = "BaseProperty"; //BaseProperty.class.getSimpleName();
diff --git a/src/main/java/org/gcube/informationsystem/model/impl/entities/ResourceImpl.java b/src/main/java/org/gcube/informationsystem/model/impl/entities/ResourceImpl.java
index 283aad4..daf1cf0 100644
--- a/src/main/java/org/gcube/informationsystem/model/impl/entities/ResourceImpl.java
+++ b/src/main/java/org/gcube/informationsystem/model/impl/entities/ResourceImpl.java
@@ -8,7 +8,6 @@ import java.util.List;
 import java.util.UUID;
 
 import org.gcube.informationsystem.model.impl.relations.ConsistsOfImpl;
-import org.gcube.informationsystem.model.impl.relations.IsRelatedToImpl;
 import org.gcube.informationsystem.model.reference.entities.Facet;
 import org.gcube.informationsystem.model.reference.entities.Resource;
 import org.gcube.informationsystem.model.reference.relations.ConsistsOf;
@@ -152,6 +151,7 @@ public abstract class ResourceImpl extends EntityImpl implements Resource {
 		*/
 	}
 
+	/*
 	@Override
 	public void attachResource(UUID uuid) {
 		Resource resource = new DummyResource(uuid);
@@ -163,6 +163,7 @@ public abstract class ResourceImpl extends EntityImpl implements Resource {
 		IsRelatedTo<Resource, Resource> isRelatedTo = new IsRelatedToImpl<Resource, Resource>(this, resource, null);
 		attachResource(isRelatedTo);
 	}
+	*/
 	
 	@Override
 	@SuppressWarnings({ "rawtypes", "unchecked" })
diff --git a/src/main/java/org/gcube/informationsystem/model/impl/relations/IsRelatedToImpl.java b/src/main/java/org/gcube/informationsystem/model/impl/relations/IsRelatedToImpl.java
index a3656f5..e5005ca 100644
--- a/src/main/java/org/gcube/informationsystem/model/impl/relations/IsRelatedToImpl.java
+++ b/src/main/java/org/gcube/informationsystem/model/impl/relations/IsRelatedToImpl.java
@@ -13,7 +13,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
  * @author Luca Frosini (ISTI - CNR)
  */
 @JsonTypeName(value=IsRelatedTo.NAME)
-public class IsRelatedToImpl<Out extends Resource, In extends Resource> extends
+public abstract class IsRelatedToImpl<Out extends Resource, In extends Resource> extends
 		RelationImpl<Out, In> implements IsRelatedTo<Out, In> {
 
 	/**
diff --git a/src/main/java/org/gcube/informationsystem/model/reference/entities/Entity.java b/src/main/java/org/gcube/informationsystem/model/reference/entities/Entity.java
index 6374a5a..d4e2446 100644
--- a/src/main/java/org/gcube/informationsystem/model/reference/entities/Entity.java
+++ b/src/main/java/org/gcube/informationsystem/model/reference/entities/Entity.java
@@ -4,11 +4,7 @@
 package org.gcube.informationsystem.model.reference.entities;
 
 import org.gcube.informationsystem.base.reference.entities.BaseEntity;
-import org.gcube.informationsystem.base.reference.properties.Header;
 import org.gcube.informationsystem.types.annotations.Abstract;
-import org.gcube.informationsystem.types.annotations.ISProperty;
-
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 
 
 /**
@@ -16,15 +12,9 @@ import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  * https://wiki.gcube-system.org/gcube/Facet_Based_Resource_Model#Basic_Concepts
  */
 @Abstract
-@JsonIgnoreProperties(ignoreUnknown=true)
 //@JsonDeserialize(as=EntityImpl.class) Do not uncomment to manage subclasses
 public interface Entity extends BaseEntity {
 	
 	public static final String NAME = "Entity"; //Entity.class.getSimpleName();
 	
-	/* Overriding getHeader method to create Header property in type */
-	@ISProperty(name=HEADER_PROPERTY, mandatory=true, nullable=false)
-	@Override
-	public Header getHeader();
-	
 }
diff --git a/src/main/java/org/gcube/informationsystem/model/reference/entities/Resource.java b/src/main/java/org/gcube/informationsystem/model/reference/entities/Resource.java
index 9cac2a2..b4f8907 100644
--- a/src/main/java/org/gcube/informationsystem/model/reference/entities/Resource.java
+++ b/src/main/java/org/gcube/informationsystem/model/reference/entities/Resource.java
@@ -11,12 +11,14 @@ import org.gcube.informationsystem.model.reference.relations.IsRelatedTo;
 import org.gcube.informationsystem.types.annotations.Abstract;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
  * https://wiki.gcube-system.org/gcube/Facet_Based_Resource_Model#Resources
  */
 @Abstract
+@JsonIgnoreProperties(ignoreUnknown=true)
 // @JsonDeserialize(as=ResourceImpl.class) Do not uncomment to manage subclasses
 public interface Resource extends Entity {
 	
@@ -62,10 +64,11 @@ public interface Resource extends Entity {
 	public <C extends ConsistsOf<? extends Resource, ? extends Facet>> void addFacet(C relation);
 	
 	
-	
+	/*
 	public void attachResource(UUID uuid);
 	
 	public <R extends Resource> void attachResource(R resource);
+	*/
 	
 	public <I extends IsRelatedTo<? extends Resource, ? extends Resource>> void attachResource(I relation);
 	
diff --git a/src/main/java/org/gcube/informationsystem/model/reference/properties/Property.java b/src/main/java/org/gcube/informationsystem/model/reference/properties/Property.java
index 6b7e791..552ca55 100644
--- a/src/main/java/org/gcube/informationsystem/model/reference/properties/Property.java
+++ b/src/main/java/org/gcube/informationsystem/model/reference/properties/Property.java
@@ -5,15 +5,13 @@ package org.gcube.informationsystem.model.reference.properties;
 
 import org.gcube.informationsystem.base.reference.properties.BaseProperty;
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
-
 /**
  * @author Luca Frosini (ISTI - CNR)
  * Root Class for Property types. It creates a base common type, which is useful
  * for management purpose.
  */
-// @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = ISManageable.CLASS_PROPERTY)
-@JsonIgnoreProperties(ignoreUnknown=true)
+// @JsonIgnoreProperties(ignoreUnknown=true)
+// @JsonDeserialize(as=PropertyImpl.class) Do not uncomment to manage subclasses
 public interface Property extends BaseProperty {
 	
 	public static final String NAME = "Property"; //Property.class.getSimpleName();
diff --git a/src/main/java/org/gcube/informationsystem/model/reference/relations/IsRelatedTo.java b/src/main/java/org/gcube/informationsystem/model/reference/relations/IsRelatedTo.java
index 7432c3e..e4ba8dd 100644
--- a/src/main/java/org/gcube/informationsystem/model/reference/relations/IsRelatedTo.java
+++ b/src/main/java/org/gcube/informationsystem/model/reference/relations/IsRelatedTo.java
@@ -4,12 +4,14 @@
 package org.gcube.informationsystem.model.reference.relations;
 
 import org.gcube.informationsystem.model.reference.entities.Resource;
+import org.gcube.informationsystem.types.annotations.Abstract;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
  * This Relation is for internal use only
  * https://wiki.gcube-system.org/gcube/Facet_Based_Resource_Model#isRelatedTo
  */
+@Abstract
 // @JsonDeserialize(as=IsRelatedToImpl.class) Do not uncomment to manage subclasses
 public interface IsRelatedTo<Out extends Resource, In extends Resource>
 		extends Relation<Out, In> {
diff --git a/src/main/java/org/gcube/informationsystem/types/impl/TypeDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/TypeDefinitionImpl.java
index b8662a9..1dce934 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/TypeDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/TypeDefinitionImpl.java
@@ -5,7 +5,7 @@ import java.lang.reflect.TypeVariable;
 import java.util.HashSet;
 import java.util.Set;
 
-import org.gcube.informationsystem.base.impl.ERImpl;
+import org.gcube.informationsystem.base.impl.ISManageableImpl;
 import org.gcube.informationsystem.base.reference.ISManageable;
 import org.gcube.informationsystem.base.reference.entities.BaseEntity;
 import org.gcube.informationsystem.base.reference.properties.BaseProperty;
@@ -28,7 +28,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 
 // @JsonAutoDetect(fieldVisibility=JsonAutoDetect.Visibility.ANY)
 @JsonTypeName(value=TypeDefinition.NAME)
-public abstract class TypeDefinitionImpl<ISM extends ISManageable> extends ERImpl implements TypeDefinition<ISM> {
+public abstract class TypeDefinitionImpl<ISM extends ISManageable> extends ISManageableImpl implements TypeDefinition<ISM> {
 
 	/**
 	 * Generated Serial Version UID
@@ -37,7 +37,7 @@ public abstract class TypeDefinitionImpl<ISM extends ISManageable> extends ERImp
 
 	private static Logger logger = LoggerFactory.getLogger(TypeDefinitionImpl.class);
 	
-	private final static String DESCRIPTION = "DESCRIPTION";
+	public final static String DESCRIPTION = "DESCRIPTION";
 	
 	protected String name;
 	protected String description;
diff --git a/src/main/java/org/gcube/informationsystem/types/impl/entities/EntityTypeDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/entities/EntityTypeDefinitionImpl.java
index 7449718..2c36e5c 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/entities/EntityTypeDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/entities/EntityTypeDefinitionImpl.java
@@ -1,11 +1,15 @@
 package org.gcube.informationsystem.types.impl.entities;
 
+import java.io.StringWriter;
+
 import org.gcube.informationsystem.base.reference.entities.BaseEntity;
+import org.gcube.informationsystem.base.reference.properties.Header;
 import org.gcube.informationsystem.model.reference.entities.Entity;
 import org.gcube.informationsystem.model.reference.entities.Facet;
 import org.gcube.informationsystem.model.reference.entities.Resource;
 import org.gcube.informationsystem.types.impl.TypeDefinitionImpl;
 import org.gcube.informationsystem.types.reference.entities.EntityTypeDefinition;
+import org.gcube.informationsystem.utils.ISMapper;
 
 import com.fasterxml.jackson.annotation.JsonTypeName;
 
@@ -37,4 +41,39 @@ public class EntityTypeDefinitionImpl<E extends BaseEntity> extends TypeDefiniti
 		
 	}
 
+	
+	/* 
+	 * Java does not support multiple inheritance. 
+	 * TypeDefinitionImpl is the superclass so that this class does not inherits the methods and field of BaseRelationImpl
+	 * We need to copy them. 
+	 */
+	
+	protected Header header;
+	
+	@Override
+	public Header getHeader() {
+		return header;
+	}
+	
+	@Override
+	public void setHeader(Header header){
+		this.header = header;
+	}
+	
+	@Override
+	public String toString(){
+		StringWriter stringWriter = new StringWriter();
+		try {
+			ISMapper.marshal(this, stringWriter);
+			return stringWriter.toString();
+		}catch(Exception e){
+			try {
+				ISMapper.marshal(this.header, stringWriter);
+				return stringWriter.toString();
+			} catch(Exception e1){
+				return super.toString();
+			}
+		}
+	}
+
 }
diff --git a/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
index 2d6c26e..caffbbb 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/properties/PropertyDefinitionImpl.java
@@ -7,6 +7,7 @@ import java.net.URL;
 import java.util.UUID;
 
 import org.gcube.informationsystem.base.reference.ISManageable;
+import org.gcube.informationsystem.base.reference.properties.BaseProperty;
 import org.gcube.informationsystem.model.reference.properties.Property;
 import org.gcube.informationsystem.types.Type;
 import org.gcube.informationsystem.types.Type.OType;
@@ -82,7 +83,7 @@ public final class PropertyDefinitionImpl implements PropertyDefinition {
 		Class<? extends ISManageable> type = (Class<? extends ISManageable>) method.getReturnType();
 		this.type = OType.PROPERTY.getIntValue();
 		
-		if(Property.class.isAssignableFrom(type)){
+		if(BaseProperty.class.isAssignableFrom(type)){
 			if(type != Property.class){
 				this.linkedClass = TypeBinder.getType(type);
 			}
diff --git a/src/main/java/org/gcube/informationsystem/types/impl/relations/RelationTypeDefinitionImpl.java b/src/main/java/org/gcube/informationsystem/types/impl/relations/RelationTypeDefinitionImpl.java
index 5c79db1..500dcba 100644
--- a/src/main/java/org/gcube/informationsystem/types/impl/relations/RelationTypeDefinitionImpl.java
+++ b/src/main/java/org/gcube/informationsystem/types/impl/relations/RelationTypeDefinitionImpl.java
@@ -1,6 +1,9 @@
 package org.gcube.informationsystem.types.impl.relations;
 
+import java.io.StringWriter;
+
 import org.gcube.informationsystem.base.reference.entities.BaseEntity;
+import org.gcube.informationsystem.base.reference.properties.Header;
 import org.gcube.informationsystem.base.reference.relations.BaseRelation;
 import org.gcube.informationsystem.model.reference.relations.ConsistsOf;
 import org.gcube.informationsystem.model.reference.relations.IsRelatedTo;
@@ -9,6 +12,7 @@ import org.gcube.informationsystem.types.TypeBinder;
 import org.gcube.informationsystem.types.impl.TypeDefinitionImpl;
 import org.gcube.informationsystem.types.reference.entities.EntityTypeDefinition;
 import org.gcube.informationsystem.types.reference.relations.RelationTypeDefinition;
+import org.gcube.informationsystem.utils.ISMapper;
 
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonTypeName;
@@ -63,28 +67,65 @@ public class RelationTypeDefinitionImpl<Out extends BaseEntity, In extends BaseE
 		return targetType;
 	}
 	
+	
+	/* 
+	 * Java does not support multiple inheritance. 
+	 * TypeDefinitionImpl is the superclass so that this class does not inherits the methods and field of BaseRelationImpl
+	 * We need to copy them. 
+	 */
+	
+	protected Header header;
+	
+	@Override
+	public Header getHeader() {
+		return header;
+	}
+	
+	@Override
+	public void setHeader(Header header){
+		this.header = header;
+	}
+	
+	@Override
+	public String toString(){
+		StringWriter stringWriter = new StringWriter();
+		try {
+			ISMapper.marshal(this, stringWriter);
+			return stringWriter.toString();
+		}catch(Exception e){
+			try {
+				ISMapper.marshal(this.header, stringWriter);
+				return stringWriter.toString();
+			} catch(Exception e1){
+				return super.toString();
+			}
+		}
+	}
+
+	protected EntityTypeDefinition<Out> source;
+	protected EntityTypeDefinition<In> target;
+	
 	@Override
 	public EntityTypeDefinition<Out> getSource() {
-		// TODO Auto-generated method stub
-		return null;
+		return source;
 	}
 
+
 	@Override
 	public void setSource(EntityTypeDefinition<Out> source) {
-		// TODO Auto-generated method stub
-		
+		this.source = source;
 	}
 
+
 	@Override
 	public EntityTypeDefinition<In> getTarget() {
-		// TODO Auto-generated method stub
-		return null;
+		return target;
 	}
 
+
 	@Override
 	public void setTarget(EntityTypeDefinition<In> target) {
-		// TODO Auto-generated method stub
-		
+		this.target = target;
 	}
 	
 }
diff --git a/src/main/java/org/gcube/informationsystem/types/reference/TypeDefinition.java b/src/main/java/org/gcube/informationsystem/types/reference/TypeDefinition.java
index 46de7cb..b63470b 100644
--- a/src/main/java/org/gcube/informationsystem/types/reference/TypeDefinition.java
+++ b/src/main/java/org/gcube/informationsystem/types/reference/TypeDefinition.java
@@ -2,7 +2,6 @@ package org.gcube.informationsystem.types.reference;
 
 import java.util.Set;
 
-import org.gcube.informationsystem.base.reference.ER;
 import org.gcube.informationsystem.base.reference.ISManageable;
 import org.gcube.informationsystem.types.annotations.Abstract;
 import org.gcube.informationsystem.types.reference.properties.PropertyDefinition;
@@ -12,7 +11,7 @@ import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 @Abstract
 @JsonIgnoreProperties(ignoreUnknown=true)
 //@JsonDeserialize(as=TypeDefinitionImpl.class) Do not uncomment to manage subclasses
-public interface TypeDefinition<ISM extends ISManageable> extends ER {
+public interface TypeDefinition<ISM extends ISManageable> extends ISManageable {
 	
 	public static final String NAME = "TypeDefinition"; //Entity.class.getSimpleName();
 	
diff --git a/src/main/java/org/gcube/informationsystem/types/reference/entities/EntityTypeDefinition.java b/src/main/java/org/gcube/informationsystem/types/reference/entities/EntityTypeDefinition.java
index 345a161..f5e586b 100644
--- a/src/main/java/org/gcube/informationsystem/types/reference/entities/EntityTypeDefinition.java
+++ b/src/main/java/org/gcube/informationsystem/types/reference/entities/EntityTypeDefinition.java
@@ -11,6 +11,6 @@ import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 @JsonDeserialize(as = EntityTypeDefinitionImpl.class)
 public interface EntityTypeDefinition<E extends BaseEntity> extends TypeDefinition<E>, BaseEntity {
 
-	public static final String NAME = "EntityDefinition"; //EntityDefinition.class.getSimpleName();
+	public static final String NAME = "EntityTypeDefinition"; //EntityTypeDefinition.class.getSimpleName();
 
 }
diff --git a/src/main/java/org/gcube/informationsystem/utils/ObjectMappingERAction.java b/src/main/java/org/gcube/informationsystem/utils/ObjectMappingERAction.java
index 9a64d26..0da8e67 100644
--- a/src/main/java/org/gcube/informationsystem/utils/ObjectMappingERAction.java
+++ b/src/main/java/org/gcube/informationsystem/utils/ObjectMappingERAction.java
@@ -3,9 +3,9 @@
  */
 package org.gcube.informationsystem.utils;
 
-import org.gcube.informationsystem.model.reference.entities.Entity;
-import org.gcube.informationsystem.model.reference.properties.Property;
-import org.gcube.informationsystem.model.reference.relations.Relation;
+import org.gcube.informationsystem.base.reference.entities.BaseEntity;
+import org.gcube.informationsystem.base.reference.properties.BaseProperty;
+import org.gcube.informationsystem.base.reference.relations.BaseRelation;
 import org.gcube.informationsystem.utils.discovery.SchemaAction;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -22,19 +22,19 @@ class ObjectMappingERAction implements SchemaAction {
 	}
 	
 	@Override
-	public <E extends Property> void managePropertyClass(Class<E> e)
+	public <P extends BaseProperty> void managePropertyClass(Class<P> e)
 			throws Exception {
 		objectMapper.registerSubtypes(e);
 	}
 
 	@Override
-	public <E extends Entity> void manageEntityClass(Class<E> e)
+	public <E extends BaseEntity> void manageEntityClass(Class<E> e)
 			throws Exception {
 		objectMapper.registerSubtypes(e);
 	}
 
 	@Override
-	public <R extends Relation<? extends Entity, ? extends Entity>> void manageRelationClass(
+	public <R extends BaseRelation<? extends BaseEntity, ? extends BaseEntity>> void manageRelationClass(
 			Class<R> r) throws Exception {
 		objectMapper.registerSubtypes(r);
 	}
diff --git a/src/main/java/org/gcube/informationsystem/utils/discovery/ISMDiscovery.java b/src/main/java/org/gcube/informationsystem/utils/discovery/ISMDiscovery.java
index 0279012..8a3f509 100644
--- a/src/main/java/org/gcube/informationsystem/utils/discovery/ISMDiscovery.java
+++ b/src/main/java/org/gcube/informationsystem/utils/discovery/ISMDiscovery.java
@@ -10,9 +10,10 @@ import java.util.List;
 import java.util.Objects;
 
 import org.gcube.informationsystem.base.reference.ISManageable;
-import org.gcube.informationsystem.model.reference.entities.Entity;
+import org.gcube.informationsystem.base.reference.entities.BaseEntity;
+import org.gcube.informationsystem.base.reference.properties.BaseProperty;
+import org.gcube.informationsystem.base.reference.relations.BaseRelation;
 import org.gcube.informationsystem.model.reference.properties.Property;
-import org.gcube.informationsystem.model.reference.relations.Relation;
 import org.gcube.informationsystem.types.annotations.ISProperty;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -21,17 +22,17 @@ import org.slf4j.LoggerFactory;
  * @author Luca Frosini (ISTI - CNR)
  */
 public class ISMDiscovery<ISM extends ISManageable> {
-
+	
 	private static Logger logger = LoggerFactory.getLogger(ISMDiscovery.class);
-
+	
 	protected final Class<ISM> root;
 	protected final List<Package> packages;
 	protected final List<Class<ISM>> discovered;
-
+	
 	public List<Class<ISM>> getDiscovered() {
 		return discovered;
 	}
-
+	
 	public ISMDiscovery(Class<ISM> root) {
 		this.root = root;
 		this.packages = new ArrayList<>();
@@ -39,111 +40,111 @@ public class ISMDiscovery<ISM extends ISManageable> {
 		this.discovered = new ArrayList<>();
 		add(root);
 	}
-
+	
 	public void addPackage(Package p) {
 		packages.add(p);
 	}
-
+	
 	protected void add(Class<ISM> clz) {
 		discovered.add(clz);
 		logger.trace("+ Added {}.", clz);
 	}
-
+	
 	protected void analizeISM(Class<ISM> clz) {
 		logger.trace("Analizyng {}", clz);
-
-		if (!clz.isInterface()) {
+		
+		if(!clz.isInterface()) {
 			logger.trace("- Discarding {} that is not an interface", clz);
 			return;
 		}
-
-		if (!root.isAssignableFrom(clz)) {
+		
+		if(!root.isAssignableFrom(clz)) {
 			logger.trace("- Discarding {} because is not a {}", clz, root.getSimpleName());
 			return;
 		}
-
-		if (discovered.contains(clz)) {
+		
+		if(discovered.contains(clz)) {
 			logger.trace("- Discarding {} because was already managed", clz);
 			return;
 		}
-
+		
 		Class<?>[] interfaces = clz.getInterfaces();
-
-		for (Class<?> interfaceClass : interfaces) {
+		
+		for(Class<?> interfaceClass : interfaces) {
 			@SuppressWarnings("unchecked")
 			Class<ISM> parent = (Class<ISM>) interfaceClass;
 			analizeISM(parent);
 		}
-
-		if (root == Property.class) {
-
-			for (Method m : clz.getDeclaredMethods()) {
+		
+		if(root == Property.class) {
+			
+			for(Method m : clz.getDeclaredMethods()) {
 				m.setAccessible(true);
-				if (m.isAnnotationPresent(ISProperty.class)) {
-					if (root.isAssignableFrom(m.getReturnType())) {
+				if(m.isAnnotationPresent(ISProperty.class)) {
+					if(root.isAssignableFrom(m.getReturnType())) {
 						@SuppressWarnings("unchecked")
 						Class<ISM> type = (Class<ISM>) m.getReturnType();
 						analizeISM(type);
 					}
 				}
-
+				
 			}
 		}
 		add(clz);
 	}
-
+	
 	public void discover() throws Exception {
-		for (Package p : packages) {
+		for(Package p : packages) {
 			List<Class<?>> classes = ReflectionUtility.getClassesForPackage(p);
-			for (Class<?> clz : classes) {
+			for(Class<?> clz : classes) {
 				@SuppressWarnings("unchecked")
 				Class<ISM> ism = (Class<ISM>) clz;
 				analizeISM(ism);
 			}
 		}
-
+		
 	}
-
+	
 	public static void manageISM(SchemaAction schemaAction, List<Package> packages) throws Exception {
-		if (Objects.nonNull(packages) && packages.size() > 0) {
+		if(Objects.nonNull(packages) && packages.size() > 0) {
 			manageISM(schemaAction, packages.stream().toArray(Package[]::new));
 		} else {
 			manageISM(schemaAction);
 		}
 	}
-
+	
 	@SuppressWarnings("unchecked")
 	public static void manageISM(SchemaAction schemaAction, Package... packages) throws Exception {
-		ISMDiscovery<Property> propertyDiscovery = new ISMDiscovery<>(Property.class);
-		if (Objects.nonNull(packages))
+		ISMDiscovery<BaseProperty> propertyDiscovery = new ISMDiscovery<>(BaseProperty.class);
+		if(Objects.nonNull(packages))
 			Arrays.stream(packages).forEach(p -> propertyDiscovery.addPackage(p));
 		propertyDiscovery.discover();
-		for (Class<Property> property : propertyDiscovery.getDiscovered()) {
+		for(Class<BaseProperty> property : propertyDiscovery.getDiscovered()) {
 			logger.trace("Going to manage : {}", property);
 			schemaAction.managePropertyClass(property);
 		}
-
-		ISMDiscovery<Entity> entityDiscovery = new ISMDiscovery<>(Entity.class);
-		if (Objects.nonNull(packages))
+		
+		ISMDiscovery<BaseEntity> entityDiscovery = new ISMDiscovery<>(BaseEntity.class);
+		if(Objects.nonNull(packages))
 			Arrays.stream(packages).forEach(p -> entityDiscovery.addPackage(p));
 		entityDiscovery.discover();
-
-		for (Class<Entity> entity : entityDiscovery.getDiscovered()) {
+		
+		for(Class<BaseEntity> entity : entityDiscovery.getDiscovered()) {
 			logger.trace("Going to manage : {}", entity);
 			schemaAction.manageEntityClass(entity);
 		}
-
+		
 		@SuppressWarnings("rawtypes")
-		ISMDiscovery<Relation> relationDiscovery = new ISMDiscovery<>(Relation.class);
-		if (Objects.nonNull(packages))
+		ISMDiscovery<BaseRelation> relationDiscovery = new ISMDiscovery<BaseRelation>(BaseRelation.class);
+		if(Objects.nonNull(packages))
 			Arrays.stream(packages).forEach(p -> relationDiscovery.addPackage(p));
 		relationDiscovery.discover();
-
-		for (@SuppressWarnings("rawtypes")
-		Class<Relation> relation : relationDiscovery.getDiscovered()) {
+		
+		for(@SuppressWarnings("rawtypes")
+		Class<BaseRelation> relation : relationDiscovery.getDiscovered()) {
 			logger.trace("Going to manage : {}", relation);
 			schemaAction.manageRelationClass(relation);
 		}
 	}
-
+	
 }
diff --git a/src/main/java/org/gcube/informationsystem/utils/discovery/ReflectionUtility.java b/src/main/java/org/gcube/informationsystem/utils/discovery/ReflectionUtility.java
index 86153f9..c5fece7 100644
--- a/src/main/java/org/gcube/informationsystem/utils/discovery/ReflectionUtility.java
+++ b/src/main/java/org/gcube/informationsystem/utils/discovery/ReflectionUtility.java
@@ -139,6 +139,7 @@ public class ReflectionUtility {
 	 * @throws ClassNotFoundException
 	 *             if something went wrong
 	 */
+	@SuppressWarnings("restriction")
 	public static List<Class<?>> getClassesForPackage(String pckgname)
 	        throws ClassNotFoundException {
 	    final List<Class<?>> classes = new ArrayList<Class<?>>();
diff --git a/src/main/java/org/gcube/informationsystem/utils/discovery/SchemaAction.java b/src/main/java/org/gcube/informationsystem/utils/discovery/SchemaAction.java
index f5ea503..0e22813 100644
--- a/src/main/java/org/gcube/informationsystem/utils/discovery/SchemaAction.java
+++ b/src/main/java/org/gcube/informationsystem/utils/discovery/SchemaAction.java
@@ -3,9 +3,9 @@
  */
 package org.gcube.informationsystem.utils.discovery;
 
-import org.gcube.informationsystem.model.reference.entities.Entity;
-import org.gcube.informationsystem.model.reference.properties.Property;
-import org.gcube.informationsystem.model.reference.relations.Relation;
+import org.gcube.informationsystem.base.reference.entities.BaseEntity;
+import org.gcube.informationsystem.base.reference.properties.BaseProperty;
+import org.gcube.informationsystem.base.reference.relations.BaseRelation;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
@@ -13,10 +13,10 @@ import org.gcube.informationsystem.model.reference.relations.Relation;
  */
 public interface SchemaAction {
 
-	public <E extends Property> void managePropertyClass(Class<E> e) throws Exception;
+	public <P extends BaseProperty> void managePropertyClass(Class<P> e) throws Exception;
 	
-	public <E extends Entity> void manageEntityClass(Class<E> e) throws Exception;
+	public <E extends BaseEntity> void manageEntityClass(Class<E> e) throws Exception;
 	
-	public <R extends Relation<? extends Entity, ? extends Entity>> void manageRelationClass(Class<R> r) throws Exception;
+	public <R extends BaseRelation<? extends BaseEntity, ? extends BaseEntity>> void manageRelationClass(Class<R> r) throws Exception;
 	
 }
diff --git a/src/test/java/org/gcube/informationsystem/types/SerializationTest.java b/src/test/java/org/gcube/informationsystem/types/SerializationTest.java
index 9e41ea0..bfbbd80 100644
--- a/src/test/java/org/gcube/informationsystem/types/SerializationTest.java
+++ b/src/test/java/org/gcube/informationsystem/types/SerializationTest.java
@@ -55,4 +55,5 @@ public class SerializationTest {
 		String serialized = TypeBinder.serializeType(Header.class);
 		logger.info(serialized);
 	}
+	
 }