BozhukhaL. N. (2000) “Inequalities of the Jackson Type in the Approximation of Periodic Functions by Fejér, Rogosinski, and Korovkin Polynomials”, Ukrains’kyi Matematychnyi Zhurnal, 52(12), pp. 1596-1602. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4563 (Accessed: 22November2024).