HIRANO, N. Multiplicity of positive solutions for semilnear elliptic problems with antipodal symmetry. Topological Methods in Nonlinear Analysis, [S. l.], v. 25, n. 1, p. 155–166, 2005. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2005.007. Acesso em: 19 apr. 2024.