BOZHUKHA, L. N. On a Jackson-Type Inequality in the Approximation of a Function by Linear Summation Methods in the Space $L_2$. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 55, n. 4, p. 537–545, 2003. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3927. Acesso em: 6 dec. 2025.