APA (7th ed.) Citation

Mandino, O. (1972). The Greatest secret in the world. Bantam Books.

Chicago Style (17th ed.) Citation

Mandino, Og. The Greatest Secret in the World. New York: Bantam Books, 1972.

MLA (9th ed.) Citation

Mandino, Og. The Greatest Secret in the World. Bantam Books, 1972.

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