APA (7th ed.) Citation

Sagan, C. (1973). The cosmic connection: An extraterrestrial perspective. Dell.

Chicago Style (17th ed.) Citation

Sagan, Carl. The Cosmic Connection: An Extraterrestrial Perspective. New York: Dell, 1973.

MLA (9th ed.) Citation

Sagan, Carl. The Cosmic Connection: An Extraterrestrial Perspective. Dell, 1973.