1.
Romanyuk AS. Kolmogorov widths and bilinear approximations of the classes of periodic functions of one and many variables. Ukr. Mat. Zhurn. [Internet]. 2018Feb.25 [cited 2024Apr.25];70(2):224-35. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/1553