Kasymov, K. A., and D. N. Nurgabyl. “Asymptotic Behavior of Solutions of Linear Singularly Perturbed General Separated Boundary-Value Problems With Initial Jump”. Ukrains’kyi Matematychnyi Zhurnal 55, no. 11 (November 25, 2003): 1476–1488. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/4018.