Midodashvili, B., & Kharibegashvili, S. (2019). On the existence, uniqueness, and nonexistence of solutions of one boundary-value problem for a semilinear hyperbolic equation. Ukrains’kyi Matematychnyi Zhurnal, 71(8), 1123-1132. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/1503