R. Joy Littlewood, A Commentary on Ovid: Fasti Book 6 (Oxford University Press, 2006), p. 73; T.P. Wiseman, Remus: A Roman Myth (Cambridge University Press, 1995), p. 61 online.
Joseph Rykwert, The Idea of a Town: The Anthropology of Urban Form in Rome, Italy, and the Ancient World (MIT Press, 1988), pp. 101 and 159 online.
Daniel Ogden, Magic, Witchcraft, and Ghosts in the Greek and Roman Worlds: A Sourcebook (Oxford University Press, 2002), p. 225 online.
Craig Arthur Williams, Roman Homosexuality: Ideologies of Masculinity in Classical Antiquity p. 92 online.
Martin Henig, Religion in Roman Britain (London: BT Batsford LTD, 1984), pp. 185–186 online, with image of example.
David Wray, Catullus and the Poetics of Roman Manhood (Cambridge University Press, 2001), p. 152 online.