SUKHOROLSKYI, M. A. On the order of local approximation of functions by trigonometric polynomials that are partial sums of averaging operators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 5, p. 706–714, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5052. Acesso em: 5 dec. 2025.