Shabozov MS. Exact Jackson - Stechkin-type inequalities for 2π -periodic functions in <i>L </i><sub>2 </sub> and widths of some classes of functions. Ukr. Mat. Zhurn. [Internet]. 2011Oct.25 [cited 2024Nov.23];63(10):1434-40. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/2816