1. The Aurora Programme. Europe's Framework for Space Exploration, ESA Bulletin number 126, May 2006, European Space Agency.
2. A Journey to Inspire, Innovate, and Discover, Report of the President's Commission on Implementation of United States Space Exploration Policy, June 2004, Appendix C.
3. JAXA Vision—JAXA 2025, Japan Aerospace Exploration Agency, March 31, 2005.
4. W.J. Larson, L.K. Pranke, Human Spaceflight: Mission Analysis and Design, Space technology series, McGraw-Hill, New York, 2000 (Chapters 3 and 4).
5. V.S. Avduyevsky, G.R. Uspensky, Scientific and Economy Oriented Space Systems, Part 3, Mir Publishers, Moscow, 1988 (Chapter 3).