S. V. Pozur, “Singular Nonlinear Eigenvalue Problem for One Class of Second-Order Differential Equations”, Ukr. Mat. Zhurn., vol. 55, no. 10, pp. 1431–1438, Oct. 2003, Accessed: Apr. 09, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4012