New Haven, Conn.: Yale University Press, 1994.

Hooper, Gordon R.

The Soviet Cosmonaut Team.

Woodbridge, England: GRH Publications, 1986.

Howarth, David.

The Dreadnoughts.

Alexandria, Va.: Time-Life Books, 1979.

Hoyle, Fred.

Frontiers of Astronomy.

New York: Harper & Brothers, 1955.

Halaman tidak diketahui