Gaarder, J. 1. (1996). Sophie's world: A novel about the history of philosophy. Berkley Books.
Citazione stile Chigago Style (17a edizione)Gaarder, Jostein 1952. Sophie's World: A Novel About the History of Philosophy. New York: Berkley Books, 1996.
Citatione MLA (9a ed.)Gaarder, Jostein 1952. Sophie's World: A Novel About the History of Philosophy. Berkley Books, 1996.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.