The book Ferdinand/Elefant: Detail In Action by David Doyle is a nice addition to the library of any German armor modeler. It is packed with 80 pages of drawings, photos, and information on the Ferdinand and Elefant tank destroyers. This book also contains a small part in the front covering the Porsche Tiger, which was the predecessor of the Ferdinand/Elefant. In fact, Ferdinand Porsche designed the suspension of these three behemoths.
My favorite part of these In Action books is always looking at the pictures of the actual vehicles during the war. From these photos you can get a sense of how used these tanks were, and how the paint schemes look as compared to the museum specimens. I enjoyed looking at the photos of these giant monsters. An interesting comparison is the photos of the damaged Ferdinand #501 as seen during its capture and, later, in modern times at the museum.