APA (7th ed.) Citation

Graham, R. W. (1990). Extraterrestrial life in the universe. NASA.

Chicago Style (17th ed.) Citation

Graham, Robert W. Extraterrestrial Life in the Universe. [Washington, D.C.]: NASA, 1990.

MLA (9th ed.) Citation

Graham, Robert W. Extraterrestrial Life in the Universe. NASA, 1990.

Warning: These citations may not always be 100% accurate.