Hirano, N. (2005) “Multiplicity of positive solutions for semilnear elliptic problems with antipodal symmetry”, Topological Methods in Nonlinear Analysis, 25(1), pp. 155–166. Available at: https://apcz.umk.pl/TMNA/article/view/TMNA.2005.007 (Accessed: 16 April 2024).