World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. Jane's Fighting Aircraft of World War II. London. Studio Editions Ltd, 1998. Smith, Geoffrey G.Gas Turbines and Jet Propulsion for Aircraft, London S.E.1, Flight Publishing Co.Ltd., 1946. External links Armstrong Siddeley ASX - Flight, September 1946. ASX 1940s turbojet engines