“ On Asymptotics Construction for a Multipoint Boundary-Value Problem for a Linear Degenerate Singularly Perturbed Differential System”. Neliniini Kolyvannya 18, no. 2 (June 29, 2015): 164–175. Accessed April 12, 2026. https://nosc.imath.kiev.ua/index.php/nosc/article/view/778.