ANDRES, J. On the multivalued Poincaré operators. Topological Methods in Nonlinear Analysis, [S. l.], v. 10, n. 1, p. 171–182, 1997. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1997.027. Acesso em: 22 jul. 2024.