Treasure Hunting Buffalo Nickels by John A. Wexler, Ron Pope and Kevin Flynn. Published 1999 by Stanton Printing & Publishing.
With about 100 years of study on the series between them, the three authors have teamed up to bring you the best information available on Buffalo nickel varieties, with sections on doubled dies, over mintmarks and repunched mintmarks. Another section on How Die Varieties are Made explains and photographically illustrates the differences between the different types of die varieties found in the series. 136 pages with over 500 photographs.