[1]
S. B. Vakarchuk, “Generalized characteristics of smoothness and some extremе problems of the approximation theory of functions in the space $L_2 (R)$. I”, Ukr. Mat. Zhurn., vol. 70, no. 9, pp. 1166–1191, Sep. 2018, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/1627