Cita APA (7a ed.)

O'Callaghan, J. F. (1993). The learned king: The reign of Alfonso X of Castile. University of Pennsylvania Press.

Cita Chicago Style (17a ed.)

O'Callaghan, Joseph F. The Learned King: The Reign of Alfonso X of Castile. Philadelphia: University of Pennsylvania Press, 1993.

Cita MLA (9a ed.)

O'Callaghan, Joseph F. The Learned King: The Reign of Alfonso X of Castile. University of Pennsylvania Press, 1993.