Pozur, S. V. “Singular Nonlinear Eigenvalue Problem for One Class of Second-Order Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 55, no. 10 (October 25, 2003): 1431-1438. Accessed May 19, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4012.