1. Defense Advanced Research Projects Agency (DARPA), FedBizOpps, Commerce Business Daily (6 January 2003).
2. Northrop Grumman Corporation, Aviation Week & Space Technology, 159 (19) (November 2003), p. 13.
3. Graham Warwick, Flight International (16–22 December 2003).
4. U.S.Air Force, Engine Structural Integrity Program, Military Standard 1783B (Wright-Patterson Air Force Base, OH: Aeronautical Systems Center, 31 May 2002), 〈http://www.dscr.dla.mil/fscap2/Policy/MilHDBK1783B.pdf〉.
5. H. Kitagawa and S. Takahashi, Proceedings of the Second International Conference on Mechanical Behavior of Materials (Metals Park, OH: ASM, 1976), pp. 627–631.