YanchenkoS. Ya. “Approximation of Functions from the Isotropic Nikol’skii–Besov Classes in the Uniform and Integral Metrics”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 10 (October 25, 2015): 1423-1433. Accessed November 22, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2077.