Cita APA (7a ed.)

Schaff, P. (1964). The principle of Protestantism. United Church Press.

Cita Chicago Style (17a ed.)

Schaff, Philip. The Principle of Protestantism. Philadelphia [etc.]: United Church Press, 1964.

Cita MLA (9a ed.)

Schaff, Philip. The Principle of Protestantism. United Church Press, 1964.