LANDSTAD, M. B.; OLESEN, D. Towards a Galois theory for crossed products of $C^*$-algebras. MATHEMATICA SCANDINAVICA, [S. l.], v. 43, p. 311–321, 1978. DOI: 10.7146/math.scand.a-11783. Disponível em: https://www.mscand.dk/article/view/11783. Acesso em: 1 may. 2024.