POMPONIO, A. Singularly perturbed Neumann problems with potentials. Topological Methods in Nonlinear Analysis, [S. l.], v. 23, n. 2, p. 301–322, 2004. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2004.013. Acesso em: 27 apr. 2024.