APA (7th ed.) Citation

Bergaust, E. (1964). The next fifty years in space. Macmillan.

Chicago Style (17th ed.) Citation

Bergaust, Erik. The Next Fifty Years in Space. New York: Macmillan, 1964.

MLA (9th ed.) Citation

Bergaust, Erik. The Next Fifty Years in Space. Macmillan, 1964.