Mentynskyi, S. M. and Shuvar, B. A. (2005) “Two-Sided Approximation of Solutions of Boundary-Value Problems”, Ukrains’kyi Matematychnyi Zhurnal, 57(2), pp. 284–288. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3597 (Accessed: 6May2024).