Cita APA (7th ed.)

Zoll, D. A. (1974). Twentieth century political philosophy. Prentice-Hall.

Cita Chicago (17th ed.)

Zoll, Donald Atwell. Twentieth Century Political Philosophy. Englewood Cliffs, N. J: Prentice-Hall, 1974.

Cita MLA (9th ed.)

Zoll, Donald Atwell. Twentieth Century Political Philosophy. Prentice-Hall, 1974.