^For verification of these groups as part of the original post-punk vanguard see Heylin 2007, Siouxsie & the Banshees, Magazine and PiL, Wire; Reynolds 2013, p. 210, "... the 'post-punk vanguard'—overtly political groups like Gang of Four, Au Pairs, Pop Group ..."; Kootnikoff 2010, p. 30, "[Post-punk] bands like Joy Division, Gang of Four, and the Fall were hugely influential"; Cavanagh 2015, pp. 192–193, Gang of Four, Cabaret Voltaire, The Cure, PiL, Throbbing Gristle, Joy Division; Bogdanov, Woodstra & Erlewine 2002, p. 1337, Pere Ubu, Talking Heads; Cateforis 2011, p. 26, Devo, Throbbing Gristle, Siouxsie and the Banshees, the Slits, Wire