Graph Theory and Geography:  An Interactive View, E-Book
Sandra L. Arlinghaus, William C. Arlinghaus, Frank Harary.  Wiley-Interscience Series in Optimization and Discrete Mathematics, John Wiley & Sons, New York. (online samples available).

        "This educational text surpasses eBooks currently on the market by providing a new realm of interactive content." 
(Business Wire, April 29, 2002); 
(CBS Marketwatch, April 29, 2002)