O. I. Stepanets and A. L. Shydlich, “On some properties of convex functions”, Ukr. Mat. Zhurn., vol. 59, no. 7, pp. 920–938, Jul. 2007, Accessed: Feb. 16, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/3357