PASSASEO, D. Multiplicity of positive solutions for the equation $\delta u+\lambda u +u^{2^*-1} = 0$ in noncontractible domains. Topological Methods in Nonlinear Analysis, [S. l.], v. 2, n. 2, p. 343–366, 1993. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1993.047. Acesso em: 22 lip. 2024.