Langarshoev, M. R. (2015). On the Best Linear Methods of Approximation and the Exact Values of Widths for Some Classes of Analytic Functions in the Weighted Bergman Space.
Ukrains’kyi Matematychnyi Zhurnal,
67(10), 1366-1379.
https://umj.imath.kiev.ua/index.php/umj/article/view/2073