Παραπομπή APA

Heilbroner, R. L. (1953). Worldly philosphers.

Παραπομπή Chicago Style

Heilbroner, Robert L. Worldly Philosphers. Simon & Schuster, New York, 1953.

Παραπομπή MLA

Heilbroner, Robert L. Worldly Philosphers. 1953.