Multiple Nonnegative Solutions for a Class of Fourth-Order BVPs Via a New Topological Approach. Advances in the Theory of Nonlinear Analysis and its Application, [S. l.], v. 6, n. 3, p. 390–404, 2023. Disponível em: https://mail.atnaea.org/index.php/journal/article/view/162.. Acesso em: 13 jun. 2026.