LigunA. A. and ChernayaE. V. (1997) “On extremal problems on classes of functions defined by integral moduli of continuity”, Ukrains’kyi Matematychnyi Zhurnal, 49(11), pp. 1499–1503. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5148 (Accessed: 27July2024).