National Research Council (U.S.). Space Studies Board. Committee on Human Exploration. (1997). The human exploration of space. National Academy Press.

National Research Council (U.S.). Space Studies Board. Committee on Human Exploration. The Human Exploration of Space. Washington, D.C.: National Academy Press, 1997.

National Research Council (U.S.). Space Studies Board. Committee on Human Exploration. The Human Exploration of Space. National Academy Press, 1997.