APA (7th ed.) Citation

Mahr, K. (1975). Caves of the Druufs (American ed.). Ace Books.

Chicago Style (17th ed.) Citation

Mahr, Kurt. Caves of the Druufs. American ed. New York: Ace Books, 1975.

MLA (9th ed.) Citation

Mahr, Kurt. Caves of the Druufs. American ed. Ace Books, 1975.