B. Bekbolat, B. Kanguzhin, и N. Tokmagambetov. «TO THE QUESTION OF A MULTIPOINT MIXED BOUNDARY VALUE PROBLEM FOR A WAVE EQUATION». Academic Scientific Journal of Computer Science, no. 4 (август 10, 2019): 76–82. просмотрено декабрь 13, 2025. http://89.250.84.46/physics-mathematics/article/view/1678.