APA (7th ed.) Citation

Ellis, B. E. (1991). American psycho: A novel (First edition.). Vintage Books, a division of Penguin Random House LLC.

Chicago Style (17th ed.) Citation

Ellis, Bret Easton. American Psycho: A Novel. First edition. New York: Vintage Books, a division of Penguin Random House LLC, 1991.

MLA (9th ed.) Citation

Ellis, Bret Easton. American Psycho: A Novel. First edition. Vintage Books, a division of Penguin Random House LLC, 1991.