0-19-288003-9 Aldrete, Gregory S (2004). Daily Life In The Roman City: Rome, Pompeii, And Ostia, Greenwood Press, 2004, pp. 41-42. ISBN 031333174X Aurelius Victor
Scriptores Historiae Augustae VII, as cited by A.W. van Buren, "Graffiti at Ostia," Classical Review 37 (1923), p. 163 (Commodus 11.8 in the citation of Hannah