Bezkryla, S. I., A. N. Nesterenko, and A. V. Chaikovs’kyi. “On the Third Moduli of Continuity”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 66, no. 10, Oct. 2014, pp. 1420-4, https://umj.imath.kiev.ua/index.php/umj/article/view/2233.