Li, S., and Z. Liu. “Multiplicity of Solutions for Some Elliptic Equations Involving Critical and Supercritical Sobolev Exponents”. Topological Methods in Nonlinear Analysis, vol. 28, no. 2, Dec. 2006, pp. 235-61, https://apcz.umk.pl/TMNA/article/view/TMNA.2006.029.