Sagan, C. (1973). The cosmic connection: An extraterrestrial perspective. Dell.
Chicago Style (17th ed.) ZitazioaSagan, Carl. The Cosmic Connection: An Extraterrestrial Perspective. New York: Dell, 1973.
MLA (9th ed.) ZitazioaSagan, Carl. The Cosmic Connection: An Extraterrestrial Perspective. Dell, 1973.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.