Fragment of Io, quoted by Servius Danielis, on Eclogue 6, 47; M. R. Gale, "The Shield of Turnus ('Aeneid' 7.783-92)", Greece & Rome, vol. 44, no. 2 (October 1997), p. 191 (note); see also: Richard F. Thomas, "Theocritus, Calvus, and Eclogue 6", Classical Philology, vol. 74, no. 4 (1979), pp. 337–39https://en.wikiquote.org/wiki/Gaius_Licinius_Macer_Calvus