Dauylbayev, M., N. Aviltay, and B. Kadirbekov. “Asymptotic Estimates of the Solution of the Boundary Value Problem for Singularly Perturbed Integro-Differential Equations”. Journal of Mathematics, Mechanics and Computer Science 106, no. 2 (June 26, 2020): 39–49. Accessed July 22, 2024. https://bm.kaznu.kz/index.php/kaznu/article/view/761.