Stasyuk SA. Best $m$-term trigonometric approximation for the classes $B^r_{p,θ}$ of functions of low smoothness. Ukr. Mat. Zhurn. [Internet]. 2010Jan.25 [cited 2024Nov.23];62(1):104–111. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2846