SCHMITT, Lothar M.; WITTSTOCK, Gerd. Characterisation of matrix-ordered standard forms of W*-algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 51, p. 241–260, 1982. DOI: 10.7146/math.scand.a-11979. Disponível em: https://journals.msp.org/mscand/article/view/1674. Acesso em: 25 jul. 2026.