diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfAlreadyPresentException.java b/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfAlreadyPresentException.java
new file mode 100644
index 0000000..43a1cfc
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfAlreadyPresentException.java
@@ -0,0 +1,28 @@
+package org.gcube.informationsystem.resourceregistry.api.exceptions.relation.isparentof;
+
+import org.gcube.informationsystem.resourceregistry.api.exceptions.AlreadyPresent;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.relation.RelationAlreadyPresentException;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public class IsParentOfAlreadyPresentException extends RelationAlreadyPresentException implements AlreadyPresent {
+
+	/**
+	 * Generated Serial Version UID
+	 */
+	private static final long serialVersionUID = -244592605626665740L;
+
+	public IsParentOfAlreadyPresentException(String message) {
+		super(message);
+	}
+
+	public IsParentOfAlreadyPresentException(Throwable cause) {
+		super(cause);
+	}
+
+	public IsParentOfAlreadyPresentException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfNotFoundException.java b/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfNotFoundException.java
new file mode 100644
index 0000000..08c2b84
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/api/exceptions/relation/isparentof/IsParentOfNotFoundException.java
@@ -0,0 +1,28 @@
+package org.gcube.informationsystem.resourceregistry.api.exceptions.relation.isparentof;
+
+import org.gcube.informationsystem.resourceregistry.api.exceptions.NotFound;
+import org.gcube.informationsystem.resourceregistry.api.exceptions.relation.RelationNotFoundException;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public class IsParentOfNotFoundException extends RelationNotFoundException implements NotFound {
+
+	/**
+	 * Generated Serial Version UID
+	 */
+	private static final long serialVersionUID = -4769773168121537127L;
+
+	public IsParentOfNotFoundException(String message) {
+		super(message);
+	}
+
+	public IsParentOfNotFoundException(Throwable cause) {
+		super(cause);
+	}
+
+	public IsParentOfNotFoundException(String message, Throwable cause) {
+		super(message, cause);
+	}
+
+}