APA (7th ed.) Citation

YJ, P., & JD, F. (1997). Life: A cosmic imperative? Sky and telescope, 94(1), 42.

Chicago Style (17th ed.) Citation

YJ, Pendleton, and Farmer JD. "Life: A Cosmic Imperative?" Sky and Telescope 94, no. 1 (1997): 42.

MLA (9th ed.) Citation

YJ, Pendleton, and Farmer JD. "Life: A Cosmic Imperative?" Sky and Telescope, vol. 94, no. 1, 1997, p. 42.