The Illustrated Encyclopedia of Helicopters
The World Encyclopedia of Military Helicopters: Featuring over 80 helicopters with 500 historical and modern photographs
Whirlybirds: A History of the U.S. Helicopter Pioneers
Helicopters: Military (Aviation Factfile (Chartwell Books))
An Illustrated A-Z Directory of Military Helicopters: Featuring over 80 helicopters shown in more than 300 historical and modern photographs
Principles of Helicopter Flight
Bell 47/H-13 Sioux Helicopter: Military and Civilian Use, 1946 to the Present (Legends of Warfare: Aviation)