diff --git a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
index 06781c4..7cae122 100644
--- a/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
+++ b/src/main/java/eu/dnetlib/dhp/schema/common/ModelConstants.java
@@ -34,7 +34,7 @@ public class ModelConstants {
 	public static final String DNET_COUNTRY_TYPE = "dnet:countries";
 	public static final String DNET_REVIEW_LEVELS = "dnet:review_levels";
 	public static final String DNET_PROGRAMMING_LANGUAGES = "dnet:programming_languages";
-	public static final String DNET_EXTERNAL_REF_TYPES = "dnet:externalReference_typologies";
+	public static final String DNET_EXTERNAL_REFERENCE_TYPE = "dnet:externalReference_typologies";
 
 	public static final String SYSIMPORT_CROSSWALK_REPOSITORY = "sysimport:crosswalk:repository";
 	public static final String SYSIMPORT_CROSSWALK_ENTITYREGISTRY = "sysimport:crosswalk:entityregistry";