Butler, Amy. "USAF Chief Defends F-22 Need, Capabilities."Archivado el 19 de agosto de 2011 en Wayback Machine. Aviation Week, 17 February 2009. "... noting that Raptors are ready for a mission around 62 percent of the time, if its low-observable requirements are met (DAILY, Nov. 20). Reliability goes up above 70 percent for missions with lower stealth demands."
Carlson, Maj. Gen. Bruce. "Subject: Stealth Fighters". U.S. Department of Defense Office of the Assistant Secretary of Defense (Public Affairs) News Transcript. Retrieved: 16 July 2007.
lockheedmartin.com (2011). «Why F-22?». Lockheed Martin(en inglés). Archivado desde el original el 28 de abril de 2009. Consultado el 4 de enero de 2012.
lockheedmartin.com (2011). «Why F-22?». Lockheed Martin(en inglés). Archivado desde el original el 28 de abril de 2009. Consultado el 4 de enero de 2012.
Butler, Amy. "USAF Chief Defends F-22 Need, Capabilities."Archivado el 19 de agosto de 2011 en Wayback Machine. Aviation Week, 17 February 2009. "... noting that Raptors are ready for a mission around 62 percent of the time, if its low-observable requirements are met (DAILY, Nov. 20). Reliability goes up above 70 percent for missions with lower stealth demands."