APA (7th ed.) Citation

Semper, I. J. (1939). The battle of the books. National Organization for Decent Literature.

Chicago Style (17th ed.) Citation

Semper, Isidore Joseph. The Battle of the Books. Dubuque, Iowa: National Organization for Decent Literature, 1939.

MLA (8th ed.) Citation

Semper, Isidore Joseph. The Battle of the Books. National Organization for Decent Literature, 1939.