LANDSTAD, Magnus B.; OLESEN, Dorte. 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: 5 dec. 2025.