VAN DER PUTTEN, R. A note on the local invertibility of Sobolev functions. MATHEMATICA SCANDINAVICA, [S. l.], v. 83, n. 2, p. 255–264, 1998. DOI: 10.7146/math.scand.a-13854. Disponível em: https://www.mscand.dk/article/view/13854. Acesso em: 2 may. 2024.