“Approximation of Classes of Poisson Integrals by Fejer Sums”. Visnyk of V. N. Karazin Kharkiv National University. Ser. Mathematics, Applied Mathematics and Mechanics 87 (February 10, 2018): 4–12. Accessed October 24, 2026. https://periodicals.karazin.ua/mech_math/article/view/11602.