Koshanov, B., Koshanova, G., Azimkhan, G., & Segizbayeva, R. (2020). SOLVABILITY OF BOUNDARY VALUE PROBLEMS WITH NON-LOCAL CONDITIONS FOR MULTIDIMENSIONAL HYPERBOLIC EQUATIONS. Известия НАН РК. Серия физико-математическая, (2), 103–111. извлечено от http://189185.vm7pq.group/physics-mathematics/article/view/412