I was looking at my bookshelf for books with numbers in the titles and found two titles I've read and referenced heavily and one title I've thumbed through on occasion. I'm sure you make a good guess about the one I need to read, review, and put to use!
My photography professor would have us go to the photographic section of the library to peruse the books, there is always a path hiding somewhere in books about photography. Big fan of hiking too.