BARTSCH, T.; DANCER, E. N. Poincaré-Hopf type formulas on convex sets of Banach spaces. Topological Methods in Nonlinear Analysis, [S. l.], v. 34, n. 2, p. 213–229, 2009. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2009.039. Acesso em: 19 apr. 2024.