ARCHBOLD, R. J. On commuting $C^*$-algebras of operators. MATHEMATICA SCANDINAVICA, [S. l.], v. 38, p. 106–114, 1976. DOI: 10.7146/math.scand.a-11621. Disponível em: https://www.mscand.dk/article/view/11621. Acesso em: 29 apr. 2024.