GABOR, Grzegorz; PIETKUN, Radosław. Periodic solutions of differential inclusions with retards. Topological Methods in Nonlinear Analysis, [S. l.], v. 16, n. 1, p. 103–123, 2000. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2000.033. Acesso em: 3 jul. 2025.