The DH4 /DH9 File, by Ray Sturtivant and Gordon Page
The D.H.4, D.H.9 & D.H.9A were built in very large numbers and formed a major part of the Royal Flying Corps, Royal Naval Air Service and Royal Air Force. Over 4,000 were built and, as well as forming the basis of the US Army Air Corps in the 1920s, were also used to found the Air Mail Service.
300 pages, 466 photos and graphics. 4 pages of drawings.