VakarchukS. B. “On Exact Order Estimates of <em class="a-Plus-plus">N</Em&gt;-Widths of Classes of Functions Analytic in a Simply Connected Domain”. Ukrains’kyi Matematychnyi Zhurnal 48, no. 4 (April 25, 1996): 543-547. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5318.