Zhang, L., X. Tang, and Y. Chen. “Infinitely Many Solutions for Quasilinear Schrödinger Equations under Broken Symmetry Situation”. Topological Methods in Nonlinear Analysis, vol. 48, no. 2, Sept. 2016, pp. 539-54, https://apcz.umk.pl/TMNA/article/view/TMNA.2016.057.