APA (7th ed.) Citation

Barber, W. J. (1967). A history of economic thought. Penguin Books.

Chicago Style (17th ed.) Citation

Barber, William J. A History of Economic Thought. New York: Penguin Books, 1967.

MLA (9th ed.) Citation

Barber, William J. A History of Economic Thought. Penguin Books, 1967.