Cita APA (7th ed.)

Keller, J. E. (1967). Alfonso X, El sabio. Twayne Publishers.

Cita Chicago (17th ed.)

Keller, John Esten. Alfonso X, El Sabio. New York: Twayne Publishers, 1967.

Cita MLA (9th ed.)

Keller, John Esten. Alfonso X, El Sabio. Twayne Publishers, 1967.