Roland Aircraft of WWI: A Centennial Perspective on Great War Airplanes (Great War Aviation Centennial Series): Jack Herris, Bob Pearson, Aaron Weaver, Steve Anderson: 9781935881209: Amazon.com: Books
Kappa 77 KP 2U-SOVA - Wikipedia
Aircraft of World War I 1914-1918 (Essential Identification Guide): Herris, Jack, Pearson, Rob: 9781906626655: Amazon.com: Books