GEEN, William L. Compact groups of automorphisms of von Neumann algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 37, p. 284–296, 1975. DOI: 10.7146/math.scand.a-11607. Disponível em: https://journals.msp.org/mscand/article/view/2066. Acesso em: 25 jul. 2026.