I. P. Gavrilyuk, A. V. Klymenko, V. L. Makarov, and N. O. Rossokhata, “FD-method for an eigenvalue problem with nonlinear potential”, Ukr. Mat. Zhurn., vol. 59, no. 1, pp. 14–28, Jan. 2007, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3289