International Encyclopedia of Aviation War in the air : aerial wonders of our time Black wings : the American black in aviation Flying machines : the picture of the men, women and machines which first conquered space Air forces of the world : an illustrated directory of all the world's military air powers Aircraft aircraft Chronology of significant aerospace events March 1903-December 1971 Air power : a Concise History sky their frontier : the Story of the World's Pioneer Airlines and Routes 1920-1940 Flight: The story of aviation in pictures and text story of aircraft : seven decades of powered flight 75 Years of Aerospace Research in the Netherlands : 1919-1994