diff --git a/src/main/java/org/gcube/informationsystem/orientdb/hooks/ConsistsOfHook.java b/src/main/java/org/gcube/informationsystem/orientdb/hooks/ConsistsOfHook.java
index 95bc5b4..5fd4aa9 100644
--- a/src/main/java/org/gcube/informationsystem/orientdb/hooks/ConsistsOfHook.java
+++ b/src/main/java/org/gcube/informationsystem/orientdb/hooks/ConsistsOfHook.java
@@ -3,10 +3,10 @@
  */
 package org.gcube.informationsystem.orientdb.hooks;
 
-import org.gcube.informationsystem.model.impl.embedded.PropagationConstraintImpl;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.AddConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.RemoveConstraint;
+import org.gcube.informationsystem.model.impl.properties.PropagationConstraintImpl;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.AddConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.RemoveConstraint;
 import org.gcube.informationsystem.model.reference.relation.ConsistsOf;
 import org.gcube.informationsystem.model.reference.relation.IsRelatedTo;
 
diff --git a/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java b/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
index 7e981d5..4f662b7 100644
--- a/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
+++ b/src/main/java/org/gcube/informationsystem/orientdb/hooks/HeaderHook.java
@@ -6,8 +6,8 @@ package org.gcube.informationsystem.orientdb.hooks;
 import java.util.Calendar;
 import java.util.UUID;
 
-import org.gcube.informationsystem.model.reference.embedded.Header;
 import org.gcube.informationsystem.model.reference.entity.Entity;
+import org.gcube.informationsystem.model.reference.properties.Header;
 import org.gcube.informationsystem.model.reference.relation.Relation;
 
 import com.orientechnologies.common.log.OLogManager;
diff --git a/src/main/java/org/gcube/informationsystem/orientdb/hooks/IsRelatedToHook.java b/src/main/java/org/gcube/informationsystem/orientdb/hooks/IsRelatedToHook.java
index 9c5b49e..0c1fcc6 100644
--- a/src/main/java/org/gcube/informationsystem/orientdb/hooks/IsRelatedToHook.java
+++ b/src/main/java/org/gcube/informationsystem/orientdb/hooks/IsRelatedToHook.java
@@ -1,9 +1,9 @@
 package org.gcube.informationsystem.orientdb.hooks;
 
-import org.gcube.informationsystem.model.impl.embedded.PropagationConstraintImpl;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.AddConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.RemoveConstraint;
+import org.gcube.informationsystem.model.impl.properties.PropagationConstraintImpl;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.AddConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.RemoveConstraint;
 import org.gcube.informationsystem.model.reference.relation.IsRelatedTo;
 
 import com.orientechnologies.orient.core.db.document.ODatabaseDocument;
diff --git a/src/main/java/org/gcube/informationsystem/orientdb/hooks/RelationHook.java b/src/main/java/org/gcube/informationsystem/orientdb/hooks/RelationHook.java
index a8acb89..08061d0 100644
--- a/src/main/java/org/gcube/informationsystem/orientdb/hooks/RelationHook.java
+++ b/src/main/java/org/gcube/informationsystem/orientdb/hooks/RelationHook.java
@@ -3,9 +3,9 @@
  */
 package org.gcube.informationsystem.orientdb.hooks;
 
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.AddConstraint;
-import org.gcube.informationsystem.model.reference.embedded.PropagationConstraint.RemoveConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.AddConstraint;
+import org.gcube.informationsystem.model.reference.properties.PropagationConstraint.RemoveConstraint;
 import org.gcube.informationsystem.model.reference.relation.Relation;
 
 import com.orientechnologies.common.log.OLogManager;