I repeat myself when I say that things like this preclude getting sources from other books, and when one writes a book on the investigation, himself becomes the authority on the matter. When I do such things myself, having never written a book on any of my investigations, I'm typically never taken as an authority on my own conclusions, particularly because I can't cite any other authoritative book as a source. I can never give a single book as a single source of any particular bit of information because I typically triangulate among several--my conclusions are my own, not a conclusion found in any book. But I will say here and now that the conclusions I reach are my own, and I am the originating source of my own conclusions, as based on thorough investigation, nonetheless.
National Media Museum blog about this topic
Sean Palmer's article
Getty Museum article
Roger Fenton, Wikipedia