Romanyuk, V. S. “Weighted Approximation in Mean of Classes of Analytic Functions by Algebraic Polynomials and Finite-Dimensional Subspaces”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 5 (May 25, 1999): 645–662. Accessed May 21, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4651.