ABBONDANDOLO, Alberto; ROT, Thomas. The homotopy classification of proper Fredholm maps of index one. Topological Methods in Nonlinear Analysis, [S. l.], v. 59, n. 2A, p. 585–621, 2022. DOI: 10.12775/TMNA.2020.068. Disponível em: https://apcz.umk.pl/TMNA/article/view/37327. Acesso em: 28 jun. 2025.