Said to be found at Cumae
Alexander, Christine. 1928. Jewelry: The Art of the Goldsmith in Classical Times as Illustrated in the Museum Collection. p. 11, fig. 12, New York: The Metropolitan Museum of Art.
Picón, Carlos A. and Seán Hemingway. 2016. Pergamon and the Hellenistic Kingdoms of the Ancient World no. 85, pp. 170–71, New York: The Metropolitan Museum of Art.