Bozhukha LN. Inequalities of the Jackson Type in the Approximation of Periodic Functions by Fejér, Rogosinski, and Korovkin Polynomials. Ukr. Mat. Zhurn. [Internet]. 2000 Dec. 25 [cited 2025 Dec. 5];52(12):1596-602. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4563