1 2 Wallace, Dan (2008), "Cadre", in Dougall, Alastair, The DC Comics Encyclopedia, New York: Dorling Kindersley, p. 64, ISBN 0-7566-4119-5, OCLC 213309017 ↑ Jimenez, Phil (2008), "Extremists, The", in Dougall, Alastair, The DC Comics Encyclopedia, New York: Dorling Kindersley, p. 117, ISBN 0-7566-4119-5, OCLC 213309017