Serdyuk, A. S., & Stepanyuk, T. A. (2014). Estimations of the Best Approximations for the Classes of Infinitely Differentiable Functions in Uniform and Integral Metrics. Ukrains’kyi Matematychnyi Zhurnal, 66(9), 1244–1256. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/2215