Passaseo D. Multiplicity of positive solutions for the equation $\delta u+\lambda u +u^{2^*-1} = 0$ in noncontractible domains. TMNA [Internet]. 1993 Dec. 1 [cited 2024 Jul. 22];2(2):343-66. Available from: https://apcz.umk.pl/TMNA/article/view/TMNA.1993.047