Sterjo, Edger. “Multiplicity of Solutions for Polyharmonic Dirichlet Problems With Exponential Nonlinearities and Broken Symmetry”. Topological Methods in Nonlinear Analysis 50, no. 1 (June 25, 2017): 27–63. Accessed April 25, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.2017.018.