BARTOLO, Rossella, CANDELA, Anna Maria and SALVATORE, Addolorata. Multiple solutions for perturbed quasilinear elliptic problems. Topological Methods in Nonlinear Analysis. Online. 26 February 2023. Vol. 61, no. 1, pp. 549 - 574. [Accessed 22 July 2024]. DOI 10.12775/TMNA.2022.069.