Zhyhallo TV, Kharkevych YI. Approximation of (ψ, β)-differentiable functions by Poisson integrals in the uniform metric. Ukr. Mat. Zhurn. [Internet]. 2009Nov.25 [cited 2024Apr.26];61(11):1497-515. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3117