APA (7th ed.) Citation

Porter, K. W. (1931). John Jacob Astor, business man. Harvard university press.

Chicago Style (17th ed.) Citation

Porter, Kenneth Wiggins. John Jacob Astor, Business Man. Cambridge, Mass.: Harvard university press, 1931.

MLA (9th ed.) Citation

Porter, Kenneth Wiggins. John Jacob Astor, Business Man. Harvard university press, 1931.