GROLI, A.; SQUASSINA, M. On the existence of two solutions for a general class of jumping problems. Topological Methods in Nonlinear Analysis, [S. l.], v. 21, n. 2, p. 325–344, 2003. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2003.020. Acesso em: 26 apr. 2024.