APA (7th ed.) Citation

Romulo, C. P. (1961). I walked with heroes. Avon Book.

Chicago Style (17th ed.) Citation

Romulo, Carlos Peña. I Walked with Heroes. New York: Avon Book, 1961.

MLA (9th ed.) Citation

Romulo, Carlos Peña. I Walked with Heroes. Avon Book, 1961.