BOUCHAL, Lydia, Karima MEBARKI, and Svetlin Georgiev GEORGIEV. “Nonnegative Solutions for a Class of Fourth Order Singular Eigenvalue Problems”. Studia Universitatis Babeș-Bolyai Mathematica 69, no. 4 (December 13, 2024): 905–912. Accessed February 5, 2025. https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/8609.