APA (7th ed.) Citation

Heilbroner, R. L. (1972). The worldly philosophers (4th ed.). A Touchstone Book.

Chicago Style (17th ed.) Citation

Heilbroner, Robert L. The Worldly Philosophers. 4th ed. New York: A Touchstone Book, 1972.

MLA (9th ed.) Citation

Heilbroner, Robert L. The Worldly Philosophers. 4th ed. A Touchstone Book, 1972.