[1]
A. M. Kogan, β€œOn the best approximation of classes $W^r H^{Ο‰}$ by algebraic polynomials in the space $L_1$”, Ukr. Mat. Zhurn., vol. 51, no. 11, pp. 1456–1466, Nov. 1999, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/4747