PERERA, Kanishka and SPORTELLI, Caterina. A multiplicity result for critical elliptic problems involving differences of local and nonlocal operators. Topological Methods in Nonlinear Analysis. Online. 16 June 2024. Vol. 63, no. 2, pp. 717 - 731. [Accessed 15 December 2025]. DOI 10.12775/TMNA.2023.037.