Rezendes, "Tracking & The Art of Seeing," a bit over 300 pages, 2d edition, 1999. "Tracking & The Art of Seeing" makes my short list. It is a visual feast, with wonderfully clear photographs of things at best diagrammed, but usually just described in words, in other tracking books. If pictures are worth a thousand words, then this 300 plus page book full of great photographs is an encyclopedia of tracking. In and around the photographs is a wealth of tracking notes. Highly recommended.