Aitenova, G.M., Zh.A. Sartabanov, B.Zh. Omarova, and A.Kh. Zhumagaziyev. “Stability and Existence of Multiperiodic Solutions for Second-Order Linear Equations With a Diagonal Differentiation Operator”. Bulletin of the Karaganda University. Mathematics Series 121, no. 1 (March 30, 2026): 23–36. Accessed April 4, 2026. https://mts.buketov.edu.kz/mathematics-vestnik/article/view/1094.