[1]
V. V. Volchkov, β€œOn exact constants in Jackson-type inequalities in the space $L^2$”, Ukr. Mat. Zhurn., vol. 47, no. 1, pp. 108–110, Jan. 1995, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5388