BabenkoV. F., KofanovV. A., and PichugovS. A. 2006. “Exact Inequalities for Derivatives of Functions of Low Smoothness Defined on an Axis and a Semiaxis”. Ukrains’kyi Matematychnyi Zhurnal 58 (3), 291–302. https://umj.imath.kiev.ua/index.php/umj/article/view/3454.