1. National Commission on Space. Pioneering the space frontier. New York: Bantam Books, 1986.
2. Lewis J. et al., editors. Resources of near Earth space. Tucson: University of Arizona Press, 1993.
3. The high frontier;O'Neill,1978
4. Johnson RD, Holbrow C. editor. Space settlements – A design study. NASA SP-413, 1977.
5. Boston PJ. editor. The case for Mars. AAS Science and Technology Series, vol. 57. 1984.