Ostrovskaya О. V. Approximation of continuous functions defined on the real axis by generalized Zygmund operators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 51, n. 11, p. 1505–1512, 1999. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4752. Acesso em: 5 dec. 2025.