diff --git a/core-parser/src/main/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMap.java b/core-parser/src/main/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMap.java
index 9dd6218ae..4870bf73e 100644
--- a/core-parser/src/main/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMap.java
+++ b/core-parser/src/main/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMap.java
@@ -9,7 +9,9 @@
 import org.uniprot.core.uniprotkb.UniProtKBReference;
 
 public class EntryReferenceMap implements NamedValueMap {
-    static final List<String> FIELDS = Arrays.asList("lit_pubmed_id");
+    static final String LIT_PUBMED_ID = "lit_pubmed_id";
+    static final String LIT_DOI_ID = "lit_doi_id";
+    static final List<String> FIELDS = Arrays.asList(LIT_PUBMED_ID, LIT_DOI_ID);
     private final List<UniProtKBReference> references;
 
     public EntryReferenceMap(List<UniProtKBReference> references) {
@@ -26,16 +28,20 @@ public Map<String, String> attributeValues() {
             return Collections.emptyMap();
         }
 
-        String result =
+        Map<CitationDatabase, String> idMaps =
                 references.stream()
                         .map(UniProtKBReference::getCitation)
                         .filter(val -> val.getCitationCrossReferences() != null)
                         .flatMap(val -> val.getCitationCrossReferences().stream())
-                        .filter(val -> val.getDatabase().equals(CitationDatabase.PUBMED))
-                        .map(CrossReference::getId)
-                        .collect(Collectors.joining("; "));
+                        .collect(
+                                Collectors.groupingBy(
+                                        CrossReference::getDatabase,
+                                        Collectors.mapping(
+                                                CrossReference::getId, Collectors.joining("; "))));
+
         Map<String, String> map = new HashMap<>();
-        map.put(FIELDS.get(0), result);
+        map.put(LIT_PUBMED_ID, idMaps.getOrDefault(CitationDatabase.PUBMED, ""));
+        map.put(LIT_DOI_ID, idMaps.getOrDefault(CitationDatabase.DOI, ""));
         return map;
     }
 
diff --git a/core-parser/src/test/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMapTest.java b/core-parser/src/test/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMapTest.java
new file mode 100644
index 000000000..751f58085
--- /dev/null
+++ b/core-parser/src/test/java/org/uniprot/core/parser/tsv/uniprot/EntryReferenceMapTest.java
@@ -0,0 +1,117 @@
+package org.uniprot.core.parser.tsv.uniprot;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.uniprot.core.parser.tsv.uniprot.EntryReferenceMap.*;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.uniprot.core.citation.Citation;
+import org.uniprot.core.citation.CitationDatabase;
+import org.uniprot.core.citation.impl.ElectronicArticleBuilder;
+import org.uniprot.core.impl.CrossReferenceBuilder;
+import org.uniprot.core.uniprotkb.UniProtKBReference;
+import org.uniprot.core.uniprotkb.impl.UniProtKBReferenceBuilder;
+
+class EntryReferenceMapTest {
+
+    private static final String FIELD_SEPARATOR = "; ";
+
+    @Test
+    void testFields() {
+        List<String> expected = Arrays.asList(LIT_PUBMED_ID, LIT_DOI_ID);
+        assertEquals(expected, FIELDS);
+    }
+
+    @Test
+    void testLitDoiId() {
+        String doiId = "doiId1";
+        List<UniProtKBReference> references = getUniProtKBReferences(CitationDatabase.DOI, doiId);
+        EntryReferenceMap mapper = new EntryReferenceMap(references);
+        Map<String, String> result = mapper.attributeValues();
+
+        verifyFieldValue(result, LIT_DOI_ID, doiId);
+    }
+
+    @Test
+    void testMultipleLitDoiId() {
+        String doiId = "doiId1";
+        String doiId2 = "doiId2";
+        List<UniProtKBReference> references =
+                getUniProtKBReferences(CitationDatabase.DOI, doiId, doiId2);
+        EntryReferenceMap mapper = new EntryReferenceMap(references);
+        Map<String, String> result = mapper.attributeValues();
+
+        verifyFieldValue(result, LIT_DOI_ID, doiId + FIELD_SEPARATOR + doiId2);
+    }
+
+    @Test
+    void testLitPubmedId() {
+        String pubmedId = "pubmedId1";
+        List<UniProtKBReference> references =
+                getUniProtKBReferences(CitationDatabase.PUBMED, pubmedId);
+        EntryReferenceMap mapper = new EntryReferenceMap(references);
+        Map<String, String> result = mapper.attributeValues();
+
+        verifyFieldValue(result, LIT_PUBMED_ID, pubmedId);
+    }
+
+    @Test
+    void testMultipleLitPubmedId() {
+        String pubmedId = "pubmedId1";
+        String pubmedId2 = "pubmedId2";
+        List<UniProtKBReference> references =
+                getUniProtKBReferences(CitationDatabase.PUBMED, pubmedId, pubmedId2);
+
+        EntryReferenceMap mapper = new EntryReferenceMap(references);
+        Map<String, String> result = mapper.attributeValues();
+
+        verifyFieldValue(result, LIT_PUBMED_ID, pubmedId + FIELD_SEPARATOR + pubmedId2);
+    }
+
+    @Test
+    void testMixedIds() {
+        String pubmedId = "pubmedId1";
+        String pubmedId2 = "pubmedId2";
+        String doiId = "doiId1";
+        String doiId2 = "doiId2";
+        List<UniProtKBReference> references =
+                getUniProtKBReferences(CitationDatabase.PUBMED, pubmedId, pubmedId2);
+        references.addAll(getUniProtKBReferences(CitationDatabase.DOI, doiId, doiId2));
+
+        EntryReferenceMap mapper = new EntryReferenceMap(references);
+        Map<String, String> result = mapper.attributeValues();
+
+        verifyFieldValue(result, LIT_PUBMED_ID, pubmedId + FIELD_SEPARATOR + pubmedId2);
+        verifyFieldValue(result, LIT_DOI_ID, doiId + FIELD_SEPARATOR + doiId2);
+    }
+
+    private List<UniProtKBReference> getUniProtKBReferences(
+            CitationDatabase database, String... ids) {
+        List<UniProtKBReference> result = new ArrayList<>();
+        for (String id : ids) {
+            Citation citation =
+                    new ElectronicArticleBuilder()
+                            .citationCrossReferencesAdd(
+                                    new CrossReferenceBuilder<CitationDatabase>()
+                                            .database(database)
+                                            .id(id)
+                                            .build())
+                            .build();
+            UniProtKBReference reference =
+                    new UniProtKBReferenceBuilder().citation(citation).build();
+            result.add(reference);
+        }
+        return result;
+    }
+
+    private void verifyFieldValue(
+            Map<String, String> result, String fieldName, String expectedValue) {
+        String resultValue = result.get(fieldName);
+        assertNotNull(resultValue);
+        assertEquals(expectedValue, resultValue);
+    }
+}