Wen, Yanyun, and Peihao Zhao. “Multiple Cylindrically Symmetric Solutions of Nonlinear Maxwell Equations”. Topological Methods in Nonlinear Analysis 62, no. 2 (November 19, 2023): 387–407. Accessed February 3, 2025. https://apcz.umk.pl/TMNA/article/view/46992.