found: Work cat.: 2004056874: Sweetman, Bill. Ultimate fighter : Lockheed Martin F-35 Joint Strike Fighter, c2004.
found: Sweetman, B. Joint strike fighter : Boeing X-32 vs Lockheed Martin X-35, c1999.
found: Airpower International Editions Journal WWW("X-32/X-35 Joint Strike fighter (JSF)")
found: Flug Revue Feb. 1999 WWW("Boeing and Lockeed Martin Battle for Joint Strike Fighter")
found: WWW 21 Sept 2004:Lockheed Martin Aeronautics Company: Product--Joint Strike Fighter Overview (2003: X-35 selected to be new Joint Strike Fighter as F-35)
found: Virtual Aircraft Museum WWW site, April 9, 2014:Lockheed-Martin F-35 Lightning II (The F-35 Lightning II -- descended from the X-35 of the Joint Strike Fighter (JSF) program -- is a single-seat, single-engined military strike fighter, a multi-role aircraft that can perform close air support, tactical bombing, and air-to-air combat. Its development is being funded by the United States, the United Kingdom, and other partner governments. It is being designed and built by an aerospace industry team led by Lockheed Martin and major partners BAE Systems and Northrop Grumman.)