BISGAARD, T. M. Characterization of perfect involution groups. MATHEMATICA SCANDINAVICA, [S. l.], v. 65, p. 245–258, 1989. DOI: 10.7146/math.scand.a-12281. Disponível em: https://www.mscand.dk/article/view/12281. Acesso em: 29 apr. 2024.