V. I. . Rukasov, “Approximation of the functions preset on the real axis by the Valle Pussen operators ”, Ukr. Mat. Zhurn., vol. 44, no. 5, pp. 682–691, May 1992, Accessed: Dec. 06, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/7965