Cita APA (7a ed.)

Erdmann, C. (1977). The Origin of the Idea of Crusade: Foreword and additional notes by Marshall W. Baldwin. Princeton University Press.

Cita Chicago Style (17a ed.)

Erdmann, Carl. The Origin of the Idea of Crusade: Foreword and Additional Notes by Marshall W. Baldwin. Princeton, New Jersey: Princeton University Press, 1977.

Cita MLA (8a ed.)

Erdmann, Carl. The Origin of the Idea of Crusade: Foreword and Additional Notes by Marshall W. Baldwin. Princeton University Press, 1977.