Aitenova, G.M., Zh.A. Sartabanov, G.A. Abdikalikova, and A. Kerimbekov. “Bounded and Multiperiodic Solutions of the System of Partial Integro-Differential Equations”. Bulletin of the Karaganda University. Mathematics Series 95, no. 3 (September 30, 2019): 8–18. Accessed August 28, 2025. http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/250.