The General Electric J73turbojet was developed by General Electric from the earlier J47 engine. Its original USAF designation was J47-21, but the innovative features (variable inlet guide vanes, and single-shell combustor case) led to its redesignation as J73.
Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN0-7509-4479-X.
Kay, Anthony L. (2007). Turbojet History and Development 1930-1960 Volume 2:USSR, USA, Japan, France, Canada, Sweden, Switzerland, Italy and Hungary (1st ed.). Ramsbury: The Crowood Press. ISBN978-1861269393.