APA (7th ed.) Citation

Zimmer, P. E. (1987). A Gathering of heroes (Ace edition.). Ace Books.

Chicago Style (17th ed.) Citation

Zimmer, Paul Edwin. A Gathering of Heroes. Ace edition. New York: Ace Books, 1987.

MLA (9th ed.) Citation

Zimmer, Paul Edwin. A Gathering of Heroes. Ace edition. Ace Books, 1987.