diff --git a/src/yang/etsi-nfv-common.yang b/src/yang/etsi-nfv-common.yang
index 85d778947c7320dd9d2942a652715ceddc195455..2ee04477ff41b3d64b4cfc68b7d306baa267a1dd 100644
--- a/src/yang/etsi-nfv-common.yang
+++ b/src/yang/etsi-nfv-common.yang
@@ -205,12 +205,16 @@ submodule etsi-nfv-common {
     base checksum-algorithm;
     description
       "SHA-384.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
   }
 
   identity sha-512 {
     base checksum-algorithm;
     description
       "SHA-512.";
+    reference
+      "GS NFV IFA011: Section 7.1.6.10 Checksum information element.";
   }
       
   /*