Savchuk, V. V., and M. V. Savchuk. “Approximation of Holomorphic Functions of Zygmund Class by Fejer Means”. Ukrains’kyi Matematychnyi Zhurnal 64, no. 8 (August 25, 2012): 1148–1152. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/2648.