POPA, Sorin. Notes on Cartan subalgebras in type $\mathrm{II}_1$ factors. Mathematica Scandinavica, Berkeley, CA, United States, v. 57, p. 171–188, 1985. DOI: 10.7146/math.scand.a-12110. Disponível em: https://journals.msp.org/mscand/article/view/1554. Acesso em: 25 jul. 2026.