"Guide to North American Diesel Locomotives" is described on the back cover that states the book "will be a valuable reference for you.  this book covers the history, development, construction and operation of diesel locomotives, from pioneering boxcab switchers of the 1920s to today's high-horsepower AC-traction-motor road locomotives.  Roster information for more than 120 historical and current railroads helps show how various railroads dieselized and what power they used on their freight and passenger trains."