Is there any difference? It's confusing having the two. It seems to me to be a glitch in tagging. Some resources have cross references tagged as "Cross Reference" and others as "Cross References". If you want to do an exhaustive search would you need to check both of these boxes, or does that result in an AND of the fields, in which case you'd need to do two different searches, first with "Cross Reference" checked and second with only "Cross References" checked? This needs to be cleaned up.
