1. A journey to inspire, innovate, and discover, Report of the President's Commission on Implementation of United States Space Exploration Policy, Washington, DC, June 2004.
2. Report of the Advisory Committee on the Future of the US Space Program, US Government Printing Office, Washington, DC, December 1990.
3. S. Rickman, Lunar Architecture Focused Trade Study Final Report, NASA/JSC, ESMD-RQ-005, October 22 2004, pp. 562–563.
4. NASA's exploration systems architecture study, Final Report, NASA-TM-2005-214060, NASA Washington, DC, November 2005.
5. Skeletal responses to space flight and the bed rest analog: a review;LeBlanc;Journal of Musculoskeletal Neuronal Interactions,2007