Cita APA (7a ed.)

Bullough, D. A., & Smith, E. (1980). The age of Charlemagne. Ferndale Editions.

Cita Chicago Style (17a ed.)

Bullough, Donald A., y Edwin Smith. The Age of Charlemagne. London: Ferndale Editions, 1980.

Cita MLA (9a ed.)

Bullough, Donald A., y Edwin Smith. The Age of Charlemagne. Ferndale Editions, 1980.