Gómez-Moreno, Carmen. Medieval Images: a Glimpse into the Symbolism and Reality of the Middle Ages. Katonah: Katonah Museum of Art, 1978. no. 7, pp. 5, 17.
Boardman, Phillip C., Marcia Cohn Growdon, and Francis X. Hartigan, ed. Culture of the Middle Ages: A Festival of the Medieval Arts. Treasures of the Middle Ages. Reno, Nevada: Sierra Nevada Museum of Art, 1978. no. 12.