Livy 8.9; for a brief introduction and English translation of the passage, see Mary Beard, J.A. North, and S.R.F. Price, Religions of Rome: A Sourcebook (Cambridge University Press, 1998), p. 157 online.
Donald G. Kyle, Spectacles of Death in Ancient Rome (Routledge, 1998), p. 87 online; Matthew Leigh, Lucan: Spectacle and Engagement (Oxford University Press, 1997), p. 131 online.
Paul Plass, The Game of Death in Ancient Rome: Arena Sport and Political Suicide (Wisconsin University Press, 1995), pp. 226–227 online; Alison Futrell, Blood in the Arena: The Spectacle of Roman Power (University of Texas Press, 1997, 2001 reprint), p. 194 et passim.
Walter Burkert, Structure and History in Greek Mythology and Ritual (University of California Press, 1979), p. 59ff. online.
Livy, 8.9.6; for the full passage with introduction and note, see Beard et al., Religions of Rome: A Sourcebook (Cambridge University Press, 1998), vol. 2, p. 157 online. See also Hendrik Wagenvoort, "The Origin of the Goddess Venus," in Pietas: Selected Studies in Roman Religion (Brill, 1980), p. 170, note 5; William Warde Fowler, The Religious Experience of the Roman People (London, 1922), p. 207.
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James B. Rives, "Magic, Religion, and Law: The Case of the Lex Cornelia de sicariis et veneficiis [it]," in Religion and Law in Classical and Christian Rome (Franz Steiner, 2006), pp. 56–57.