identifying specific Endnote library used in old document -- need to add and delete Endnote references in word doc

I use Endnote X4 on a Mac with Snow Leopard.  At some point I created multiple libraries and I may have used both in a single document that has 215 notes at this point.  Both libraries, let’s call them A and B, seem to have been updated with new items (but not always the same items I fear) around the time I was finishing the document.  For example, Library A has an item added on July 29 and Aug 4th.  Library B has other items added on July 25th.  Both libraries refer to the same topic.  I believe I may have also deleted some items from one of the libraries, Library A.  I keep getting a message asking me if I want to empty the trash.  I keep replying no (cancel) because I want to replace the deleted items but don’t know how.  I can’t even find the trash location to do this. 

So I have a major problem.  I have to add some notes to the text and enter bibliographic references from one of these two libraries. I also have to delete some notes with references.  But I don’t know which library I should use.  I don’t know if all the items in one or the other or both libraries will match the Endnote refernces in my word document. 

Is there a way to compare all the references in one library with another?  Is there a way in Word (for Mac 2011) to find out which library was used?

I have a deadline for this so I’m hoping I can resolve this easily.  

Thanks in advance for any help.

Linda 

Have you tried keeping both libraries open simultaneously while working?