Sartabanov, Zh.A., Zhumagaziyev, A.Kh., & Abdikalikova, G.A. (2020). Multiperiodic solution of linear hyperbolic in the narrow sense system with constant coefficients. Bulletin of the Karaganda University. Mathematics Series, 2(98), 125–140. https://doi.org/10.31489/2020m2/125-140