R. K. Amirov, . Y. Güldü, and N. Topsakal, “On impulsive Sturm–Liouville operators with Coulomb potential and spectral parameter linearly contained in boundary conditions”, Ukr. Mat. Zhurn., vol. 62, no. 9, pp. 1155–1172, Sep. 2010, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2946