Greg Field has written a number of books on the subject of motorcycles, including several volumes dealing with Harley-Davidson, including Harley-Davidson Knucklehead, Harley-Davidson Panhead, Harley-Davidson Century, Harley-Davidson Evolution Motorcycles, Harley-Davidson Softail, Original Harley-Davidson Knucklehead, and Original Harley-Davidson Panhead. Most recently he contributed several chapters to Harley-Davidson Motorcycles: A Complete History.