SKAU, C. F. Positive self-adjoint extensions of operators affiliated with a von Neumann algebra. MATHEMATICA SCANDINAVICA, [S. l.], v. 44, p. 171–195, 1979. DOI: 10.7146/math.scand.a-11801. Disponível em: https://www.mscand.dk/article/view/11801. Acesso em: 29 apr. 2024.