LIVREA, R.; PAPAGEORGIOU, N. S.; BARLETTA, G. Resonant Neumann equations with indefinite linear part. Topological Methods in Nonlinear Analysis, [S. l.], v. 45, n. 2, p. 469–491, 2015. DOI: 10.12775/TMNA.2015.023. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2015.023. Acesso em: 28 mar. 2024.