APA (7th ed.) Citation

Eco, U. (1990). Foucalt's pendulum. Ballantine Books.

Chicago Style (17th ed.) Citation

Eco, Umberto. Foucalt's Pendulum. New York: Ballantine Books, 1990.

MLA (9th ed.) Citation

Eco, Umberto. Foucalt's Pendulum. Ballantine Books, 1990.