How do I cite a doent from a book in MLA?

I've found some research books with lots of primary sources, but the primary sources are all compiled from different sources themselves. So do I cite both? Or just the book I'm getting the doents from? I've been on Noodletools and the Rice website: they all say that there is a difference between citing a book and a work from an anthology/collection. Would a book of doents from different sources be considered a "collection"?