HANCHE-OLSEN, Harald. Split faces and ideal structure of operator algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 48, p. 137–144, 1981. DOI: 10.7146/math.scand.a-11906. Disponível em: https://journals.msp.org/mscand/article/view/1719. Acesso em: 25 jul. 2026.