O’UCHI, M. Coverings of foliations anf associated $C^*$-algebras. MATHEMATICA SCANDINAVICA, [S. l.], v. 58, p. 69–76, 1986. DOI: 10.7146/math.scand.a-12130. Disponível em: https://www.mscand.dk/article/view/12130. Acesso em: 19 apr. 2024.