NASA SP-168. Washington, D.C.: U.S. Government Printing Office, 1968.

Dixon, Don.

Universe.

Boston: Houghton Mifflin, 1981.

Dornberger, Walter.

V-2.

New York: Viking Press, 1954.

Dunne, James A., and Eric Burgess.

The Voyage of Mariner 10.

NASA SP-424. Washington, D.C.: U.S. Government Printing Office, 1978.

Shafi da ba'a sani ba