APA (7th ed.) Citation

Gaarder, J., & Møller, P. (1994). Sophie's world: A novel about the history of philosophy. Farrar, Straus and Giroux.

Chicago Style (17th ed.) Citation

Gaarder, Jostein, and Paulette Møller. Sophie's World: A Novel About the History of Philosophy. New York: Farrar, Straus and Giroux, 1994.

MLA (9th ed.) Citation

Gaarder, Jostein, and Paulette Møller. Sophie's World: A Novel About the History of Philosophy. Farrar, Straus and Giroux, 1994.