APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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