Stasyuk SA. Best <i>M</i>-term orthogonal trigonometric approximations of the classes <i>B</i>^Ω<sub>p,θ</sub&gt; of periodic functions of many variables. Ukr. Mat. Zhurn. [Internet]. 2008May25 [cited 2024May6];60(5):647 -. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3183