APA (7th ed.) Citation

Keene. (1947). The secret of the forgotten city. Grosset and Dunlap.

Chicago Style (17th ed.) Citation

Keene. The Secret of the Forgotten City. New York: Grosset and Dunlap, 1947.

MLA (8th ed.) Citation

Keene. The Secret of the Forgotten City. Grosset and Dunlap, 1947.

Warning: These citations may not always be 100% accurate.