Cita APA (7a ed.)

Piper, O. A. (1965). Protestantism in an ecumenical age: Its root, its right, its task. Fortress.

Cita Chicago Style (17a ed.)

Piper, Otto A. Protestantism in an Ecumenical Age: Its Root, Its Right, Its Task. Philadelphia: Fortress, 1965.

Cita MLA (9a ed.)

Piper, Otto A. Protestantism in an Ecumenical Age: Its Root, Its Right, Its Task. Fortress, 1965.