Djeffal, Selma Hadjer, and Aissa Benselhoub. “Research of the Fučik Spectrum for the (p,q)-Laplacian Operator by Min-Max Theory”. Technology audit and production reserves 3, no. 2(71) (April 28, 2023): 30–35. Accessed May 20, 2024. https://journals.uran.ua/tarp/article/view/277565.