APA (7th ed.) Citation

Hart, M. H., & Zuckerman, B. (1995). Extraterrestrials - where are they? (2nd edition.). Cambridge University Press.

Chicago Style (17th ed.) Citation

Hart, Michael H., and Ben Zuckerman. Extraterrestrials - Where Are They? 2nd edition. Cambridge: Cambridge University Press, 1995.

MLA (8th ed.) Citation

Hart, Michael H., and Ben Zuckerman. Extraterrestrials - Where Are They? 2nd edition. Cambridge University Press, 1995.