Serdyuk AS. Approximation of Periodic Functions of High Smoothness by Interpolation Trigonometric Polynomials in the Metric of $L_1$. Ukr. Mat. Zhurn. [Internet]. 2000 Jul. 25 [cited 2025 Apr. 9];52(7):994-8. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4501