MurachA. A., PelekhataO. B., and SoldatovV. O. “Approximation Properties of Solutions to Multipoint Boundary-Value Problems”. Ukrains’kyi Matematychnyi Zhurnal 73, no. 3 (March 11, 2021): 341 - 353. Accessed November 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/6505.