diff --git a/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/scholexplorer/DLIUnknown.java b/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/scholexplorer/DLIUnknown.java
index e9b670d03..5da599427 100644
--- a/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/scholexplorer/DLIUnknown.java
+++ b/dhp-schemas/src/main/java/eu/dnetlib/dhp/schema/scholexplorer/DLIUnknown.java
@@ -2,10 +2,8 @@
 package eu.dnetlib.dhp.schema.scholexplorer;
 
 import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
+import java.util.stream.Collectors;
 
 import org.apache.commons.lang3.StringUtils;
 
@@ -78,6 +76,25 @@ public class DLIUnknown extends Oaf implements Serializable {
 		if ("complete".equalsIgnoreCase(p.completionStatus))
 			completionStatus = "complete";
 		dlicollectedfrom = mergeProvenance(dlicollectedfrom, p.getDlicollectedfrom());
+		if (StringUtils.isEmpty(id) && StringUtils.isNoneEmpty(p.getId()))
+			id = p.getId();
+		if (StringUtils.isEmpty(dateofcollection) && StringUtils.isNoneEmpty(p.getDateofcollection()))
+			dateofcollection = p.getDateofcollection();
+
+		if (StringUtils.isEmpty(dateoftransformation) && StringUtils.isNoneEmpty(p.getDateoftransformation()))
+			dateofcollection = p.getDateoftransformation();
+		pid = mergeLists(pid, p.getPid());
+	}
+
+	protected <T> List<T> mergeLists(final List<T>... lists) {
+
+		return Arrays
+			.stream(lists)
+			.filter(Objects::nonNull)
+			.flatMap(List::stream)
+			.filter(Objects::nonNull)
+			.distinct()
+			.collect(Collectors.toList());
 	}
 
 	private List<ProvenaceInfo> mergeProvenance(
diff --git a/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/sx/graph/dmf.xml b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/sx/graph/dmf.xml
index 58defb67b..836e0b9a0 100644
--- a/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/sx/graph/dmf.xml
+++ b/dhp-workflows/dhp-graph-mapper/src/test/resources/eu/dnetlib/dhp/sx/graph/dmf.xml
@@ -1,66 +1,53 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <oai:record xmlns:oai="http://www.openarchives.org/OAI/2.0/"
-            xmlns:oaf="http://namespace.openaire.eu/oaf"
-            xmlns:dri="http://www.driver-repository.eu/namespace/dri"
-            xmlns:dc="http://purl.org/dc/elements/1.1/">
-   <oai:header>
-      <dri:repositoryId>aaadf8b3-01a8-4cc2-9964-63cfb19df3b4_UmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZXMvUmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZVR5cGU=</dri:repositoryId>
-      <dri:recordIdentifier>oai:pangaea.de:doi:10.1594/PANGAEA.821876</dri:recordIdentifier>
-      <dri:datasourceprefix>r3d100010134</dri:datasourceprefix>
-      <dri:objIdentifier>r3d100010134::000083be706192d2d839915694ecfd47</dri:objIdentifier>
-<dri:resolvedDate>2020-01-08T04:12:12.287</dri:resolvedDate>
-      <dri:dateOfCollection>2020-01-08T03:24:10.865Z</dri:dateOfCollection>
-      <oaf:datasourceprefix/>
-      <identifier>oai:pangaea.de:doi:10.1594/PANGAEA.821876</identifier>
-      <setSpec>citable</setSpec>
-   </oai:header>
-   <metadata>
-	<resource xmlns="http://datacite.org/schema/kernel-3" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://datacite.org/schema/kernel-3 http://schema.datacite.org/meta/kernel-3/metadata.xsd">
-		<identifier identifierType="doi">10.1594/pangaea.821876</identifier>
-		<creators> <creator><creatorName>Macke, Andreas</creatorName></creator><creator><creatorName>Kalisch, John</creatorName></creator> </creators>
-		<titles> <title>Total Sky Imager observations during POLARSTERN cruise ANT-XXVI/4 on 2010-05-14 with links to images</title>  </titles>
-
-<publisher>PANGAEA - Data Publisher for Earth &amp; Environmental Science</publisher>
-		<dates>
-			<date dateType="Collected">2010-05-14T00:13:47/2010-05-14T23:55:47</date>
-		</dates>
-		<subjects>
-
-	        <subject subjectScheme="Parameter">DATE/TIME</subject>
-
-	        <subject subjectScheme="Parameter">LATITUDE</subject>
-
-	        <subject subjectScheme="Parameter">LONGITUDE</subject>
-
-	        <subject subjectScheme="Parameter">Uniform resource locator/link to image</subject>
-
-	        <subject subjectScheme="Method">Total Sky Imager</subject>
-
-	        <subject subjectScheme="Campaign">ANT-XXVI/4</subject>
-
-	        <subject subjectScheme="Basis">Polarstern</subject>
-
-		</subjects>
-		<resourceType resourceTypeGeneral="dataset">dataset</resourceType>
-		<relatedIdentifiers>
-
-	            <relatedIdentifier relatedIdentifierType="dnet" relationType="isPartOf" inverseRelationType="hasPart" entityType="dataset">dli_resolver::cf447a378b0b6603593f8b0e57242695</relatedIdentifier>
-
-	            <relatedIdentifier relatedIdentifierType="URL" relationType="references" inverseRelationType="isReferencedBy" entityType="unknown">http://hs.pangaea.de/images/airphoto/ps/ps75/2010-05-14/ant-xxvi_4_2010-05-14_tsi-images-links.zip</relatedIdentifier>
-
-	            <relatedIdentifier relatedIdentifierType="dnet" relationType="references" inverseRelationType="isReferencedBy" entityType="publication">dli_resolver::f0f5975d20991cffd222c6002ddd5821</relatedIdentifier>
-
-	    </relatedIdentifiers>
-	</resource>
-</metadata>
-<oaf:about xmlns:oaf="http://namespace.dnet.eu/oaf">
-	<oaf:datainfo >
-		<oaf:completionStatus>complete</oaf:completionStatus>
-
-  <oaf:collectedFrom id="dli_________::r3d100010134" name="Pangaea" completionStatus="complete"/>
-
-	</oaf:datainfo>
-</oaf:about>
-
-
-</oai:record>
+			xmlns:oaf="http://namespace.openaire.eu/oaf"
+			xmlns:dri="http://www.driver-repository.eu/namespace/dri"
+			xmlns:dc="http://purl.org/dc/elements/1.1/">
+	<oai:header>
+		<dri:repositoryId>aaadf8b3-01a8-4cc2-9964-63cfb19df3b4_UmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZXMvUmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZVR5cGU=</dri:repositoryId>
+		<dri:recordIdentifier>oai:pangaea.de:doi:10.1594/PANGAEA.432865</dri:recordIdentifier>
+		<dri:datasourceprefix>r3d100010134</dri:datasourceprefix>
+		<dri:objIdentifier>r3d100010134::00002f60593fd1f758fb838fafb46795</dri:objIdentifier>
+		<dri:dateOfCollection>2020-02-18T03:05:02.534Z</dri:dateOfCollection>
+		<oaf:datasourceprefix/>
+		<identifier>oai:pangaea.de:doi:10.1594/PANGAEA.432865</identifier>
+		<setSpec>citable topicOceans</setSpec>
+	</oai:header>
+	<oai:metadata>
+		<resource xmlns="http://datacite.org/schema/kernel-3">
+			<identifier identifierType="doi">10.1594/pangaea.432865</identifier>
+			<titles xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+				<title>Daily sea level from coastal tide gauge station Woods_Hole in 1978 (Research quality database)</title>
+			</titles>
+			<publisher xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">PANGAEA - Data Publisher for Earth &amp; Environmental Science</publisher>
+			<publicationYear xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">2006</publicationYear>
+			<dates xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+				<date dateType="Collected">1978-01-01T12:00:00/1978-12-31T12:00:00</date>
+			</dates>
+			<creators xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+				<creator>
+					<creatorName>WOCE Sea Level, WSL</creatorName>
+				</creator>
+			</creators>
+			<subjects xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+				<subject subjectScheme="Parameter">DATE/TIME</subject>
+				<subject subjectScheme="Parameter">Sea level</subject>
+				<subject subjectScheme="Method">Tide gauge station</subject>
+				<subject subjectScheme="Campaign">SeaLevel</subject>
+				<subject subjectScheme="Project">World Ocean Circulation Experiment (WOCE)</subject>
+			</subjects>
+			<resourceType resourceTypeGeneral="Dataset"/>
+			<relatedIdentifiers>
+				<relatedIdentifier relatedIdentifierType="URL" relationType="isDocumentedBy"
+								   inverseRelationType="documents">http://store.pangaea.de/Projects/WOCE/SeaLevel_rqds/Woods_Hole.txt</relatedIdentifier>
+			</relatedIdentifiers>
+		</resource>
+	</oai:metadata>
+	<oaf:about>
+		<oaf:datainfo>
+			<oaf:collectedFrom completionStatus="complete" id="dli_________::r3d100010134" name="Pangaea"/>
+			<oaf:completionStatus>complete</oaf:completionStatus>
+			<oaf:provisionMode>collected</oaf:provisionMode>
+		</oaf:datainfo>
+	</oaf:about>
+</oai:record>
\ No newline at end of file