Washington, Office of Air Force History.

Eduard Mark of the Center for Air Force History hotly disputed this analysis.

Washington DC: Center of Air Force History, 1993.

Office of Air Force History, 1984.

Washington, D.C.: Center for Air Force History, 1992 (first edition 1951).

Office of Air Force History, 1961, republished 1983.

Office of Air Force History, 1989.

Center for Air Force History.

Washington, D.C.: Office of Air Force History, 1985.

Washington DC: Office of Air Force History, 1986.

Washington, Office of Air Force History.

Eduard Mark of the Center for Air Force History hotly disputed this analysis.

Washington DC: Center of Air Force History, 1993.

Office of Air Force History, 1984.

Washington, D.C.: Center for Air Force History, 1992 (first edition 1951).

Office of Air Force History, 1961, republished 1983.

Office of Air Force History, 1989.

Center for Air Force History.

Washington, D.C.: Office of Air Force History, 1985.

Washington DC: Office of Air Force History, 1986.