DANCER, E. N. On positive solutions of some singularly perturbed problems where the nonlinearity changes sign. Topological Methods in Nonlinear Analysis, [S. l.], v. 5, n. 1, p. 141–175, 1995. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1995.009. Acesso em: 22 jul. 2024.