BENCI, V.; GIANNONI, F. Morse theory for $C^1$-functions and Conley blocks. Topological Methods in Nonlinear Analysis, [S. l.], v. 4, n. 2, p. 365–398, 1994. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1994.034. Acesso em: 22 jan. 2022.