ANDRES, J. Nielsen number, impulsive differential equations and problem of Jean Leray. Topological Methods in Nonlinear Analysis, [S. l.], v. 56, n. 2, p. 383–400, 2020. DOI: 10.12775/TMNA.2019.112. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2019.112. Acesso em: 17 apr. 2024.