Rani, Anu, and Sarika Goyal. “Multiple Solutions for Biharmonic Critical Choquard Equation Involving Sign-Changing Weight Functions”. Topological Methods in Nonlinear Analysis 59, no. 1 (March 6, 2022): 221–260. Accessed July 3, 2024. https://apcz.umk.pl/TMNA/article/view/37623.