Little, Charles T., ed. Set in Stone: The Face in Medieval Sculpture. New York, New Haven, and London: The Metropolitan Museum of Art, 2006. no. 80, pp. 194-195.
Carr, Annemarie Weyl. "The Face Relics of John the Baptist in Byzantium and the West." Gesta 46, no. 2 (2007). p. 170, fig. 10.