Stasyuk SA. Trigonometric Widths of the Classes $B_{p,θ}^{Ω}$ of Periodic Functions of Many Variables. Ukr. Mat. Zhurn. [Internet]. 2002May25 [cited 2024Jul.27];54(5):700-5. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4109