Benci, Vieri, and Donato Fortunato. “An Eigenvalue Problem for the Schrödinger-Maxwell Equations”. Topological Methods in Nonlinear Analysis 11, no. 2 (June 1, 1998): 283–293. Accessed July 3, 2024. https://apcz.umk.pl/TMNA/article/view/TMNA.1998.019.