diff --git a/adsmanparse/translator.py b/adsmanparse/translator.py
index 3208038..fd87ead 100644
--- a/adsmanparse/translator.py
+++ b/adsmanparse/translator.py
@@ -350,8 +350,11 @@ def _get_copyright(self):
     def _special_handling(self, bibstem=None):
         # Special data handling rules on a per-bibstem basis
         if bibstem == "pds..data" or bibstem == "pdss.data":
-             uri = self.data.get("publisherIDs", {})[0].get("Identifier", "")
-             pubstring = "NASA Planetary Data System %s" % uri
+             urn = ""
+             for ident in self.data.get("publisherIDs", []):
+                 if ident.get("Identifier", "")[0:3] == "urn":
+                     urn = ident.get("Identifier", "")
+             pubstring = "NASA Planetary Data System, %s" % urn
              self.output["publication"] = pubstring
         
         elif bibstem == 'MPEC':