APA (7th ed.) Citation

Asimov, I., & Silverberg, R. (1992). The ugly little boy. Doubleday.

Chicago Style (17th ed.) Citation

Asimov, Isaac, and Robert Silverberg. The Ugly Little Boy. New York u.a: Doubleday, 1992.

MLA (9th ed.) Citation

Asimov, Isaac, and Robert Silverberg. The Ugly Little Boy. Doubleday, 1992.