Dzhumabaev, D. S. “New General Solutions of Ordinary Differential Equations and the methods of Solving the Boundary-Value Problems”. Ukrains’kyi Matematychnyi Zhurnal 71, no. 7 (July 25, 2019): 884-905. Accessed April 20, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1483.