OSAKA, Hiroyuki. Certain $C^*$-algebras with non-zero real rank and extremal richness. Mathematica Scandinavica, Berkeley, CA, United States, v. 85, n. 1, p. 79–86, 1999. DOI: 10.7146/math.scand.a-13886. Disponível em: https://journals.msp.org/mscand/article/view/942. Acesso em: 24 jul. 2026.