Cita APA (7a ed.)

Collins, R., & Godman, P. (1990). Charlemagne's heir: New perspectives on the reign of Louis the Pious (814-840). Clarendon Press.

Cita Chicago Style (17a ed.)

Collins, Roger, y Peter Godman. Charlemagne's Heir: New Perspectives on the Reign of Louis the Pious (814-840). Oxford: Clarendon Press, 1990.

Cita MLA (9a ed.)

Collins, Roger, y Peter Godman. Charlemagne's Heir: New Perspectives on the Reign of Louis the Pious (814-840). Clarendon Press, 1990.