Rukasov VI, Chaichenko SO. Approximation of the Classes $C^{{\bar \psi }} H_{\omega }$ by de la Vallée-Poussin Sums. Ukr. Mat. Zhurn. [Internet]. 2002May25 [cited 2024May18];54(5):681-9. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4107