Wernher von Braun and Frederick I. Ordway III. History of Rocketry & Space Travel. New York:Thomas Y. Crowell Company, 1969.
Arthur C. Clarke. Man and Space. New York:Time Incorporated, 1966.
Willy Ley. Rockets. Garden City, NY:Nelson Doubleday, Inc., 1965.
Astronauts Memorial Foundation. Honors and memorializes those astronauts who have sacrificed their lives for the nation and the space program. amfcse.org
National Aeronautics and Space Administration. www.nasa.gov
National Space Science Data Center. nssdc.gsfc.nasa.gov
Russian Space Web. The mission of this site is to preserve and popularize the history of space exploration and to promote the cooperation in space. www.russianspaceweb.com