there are many book on Amazon, just by typing the words dissociation or other words relevent to what you are looking for you will find hundreds of books. keep in mind though to check the copyright dates before you buy. anything that was published before may 2013 you run the risk of encountering information that has since been proven to not be part of dissociation / dissociative disorders, and also outdated, no longer used definitions, treatments, tests, diagnostics and well you get the point.

keep in mind that the more recent and up to date standards of what id dissociation, and the many new dissociation disorders including the new standards, definitions and so on for DID are the books that were published after the change over to a new mental health system (may 2013).

also something to keep in mind is some books are wrote for the direct purpose of educating treatment providers on the newer standards, definitions and all that... my point they may be a bit hard to read with all the professional wording.