Уаисов, А. Б., and Д. Н. Нургабыл. “ The Phenomenon of Initial Jump in Semi-Degenerate Boundary Value Problem With Nonlinear Conditions”. Journal of Mathematics, Mechanics and Computer Science 83, no. 4 (December 28, 2014): 52–62. Accessed October 13, 2024. https://bm.kaznu.kz/index.php/kaznu/article/view/78.