:This blind revert is unjustified. OK, I didn't see that the map had a source and so I've restored it (though it would be helpful to provide a page number). As for the other comments: 
 :1. The source clearly says "other Bulgarians". Sources can't just be interpreted to fit one's opinions - that is original research, if not falsification.  
 :2. I don't see what the problem would be of using a government source. Cvijic worked closely with the Serbian government, and his views have been given great weight in the article.  
 :3. This is not an excuse. If we do not know who the author was, we can't judge how reliable or neutral the source is. It might have been the US best specialist on the Balkans, or it might have been a Serbian diplomat in disguise (there are plenty of such cases in this period). 
 :And the argument about the version being stable is a spurious one, if the article is obviously flawed as this one was.