Cita APA (7a ed.)

(1972). The nature of proof [by] Erwin P. Bettinghaus.

Cita Chicago Style (17a ed.)

The Nature of Proof [by] Erwin P. Bettinghaus. 1972.

Cita MLA (9a ed.)

The Nature of Proof [by] Erwin P. Bettinghaus. 1972.