DZEDZEJ, Zdzisław; GRAFF, Grzegorz. Fixed point index for $G$-equivariant multivalued maps. Topological Methods in Nonlinear Analysis, [S. l.], v. 8, n. 1, p. 179–195, 1996. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1996.027. Acesso em: 4 jul. 2025.