Amirov, R. K., Güldü, Y., & Topsakal, N. (2012). On impulsive Sturm - Liouville operators with singularity and spectral parameter in boundary conditions. Ukrains’kyi Matematychnyi Zhurnal, 64(12), 1610-1629. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/2686