The designation P-40J was given
to a projected version of the P-40E which was to have a turbosupercharged
engine. This study was abandoned in May 1942 without anything
ever being built.
War Planes of the Second World
War, Fighters, Volume Four, William Green, Doubleday, 1964.
The American Fighter, Enzo Anguluci
and Peter Bowers, Orion Books, 1987.
United States Military Aircraft
since 1909, Gordon Swanborough and Peter M. Bowers, Smithsonian
Institution Press, 1989.
Curtiss Aircraft, 1907-1947,
Peter M. Bowers, Naval Institute Press, 1979.
The Curtiss P-40 Tomahawk, Ray
Wagner, Aircraft in Profile, Volume 2, Doubleday, 1965.