Derets, E.V. (2000) “On lower bounds for the widths of classes of functions defined by integral moduli of continuity”, Ukrains’kyi Matematychnyi Zhurnal, 52(3), pp. 319–328. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4421 (Accessed: 26 April 2025).