APA (7th ed.) Citation

Gaarder, J. ., & Moller, P. (1991). Sophie's world: A novel about the history of philosophy. Phoenix, 1996.

Chicago Style (17th ed.) Citation

Gaarder, Jostein , and Paulette Moller. Sophie's World: A Novel About the History of Philosophy. London: Phoenix, 1996, 1991.

MLA (9th ed.) Citation

Gaarder, Jostein , and Paulette Moller. Sophie's World: A Novel About the History of Philosophy. Phoenix, 1996, 1991.