Serdyuk, A.S. and Sokolenko, I.V. 2010. Linear approximation methods and the best approximations of the Poisson integrals of functions from the classes $H_{ω_p}$ in the metrics of the spaces $L_p$. Ukrains’kyi Matematychnyi Zhurnal. 62, 7 (Jul. 2010), 979–996.