Cen, Jinxia, Shengda Zeng, and Anouar Bahrouni. “Fractional Elliptic Obstacle Systems With Multivalued Terms and Nonlocal Operators”. Nonlinear Analysis: Modelling and Control 29, no. 5 (July 31, 2024): 1003–1025. Accessed April 7, 2025. https://www.journals.vu.lt/nonlinear-analysis/article/view/36123.