APA (7th ed.) Citation

Leonard, E. (1986). Unknown man no. 89. Penguin Books.

Chicago Style (17th ed.) Citation

Leonard, Elmore. Unknown Man No. 89. Harmondsworth u.a: Penguin Books, 1986.

MLA (9th ed.) Citation

Leonard, Elmore. Unknown Man No. 89. Penguin Books, 1986.