CHEN, J.; PAPAGEORGIOU, N. S.; ROCHA, E. M. Twin positive solutions for singular nonlinear elliptic equations. Topological Methods in Nonlinear Analysis, [S. l.], v. 35, n. 1, p. 187–201, 2010. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2010.011. Acesso em: 8 oct. 2024.