ChenF. X. “On the Generalization of Some Hermite – Hadamard Inequalities for Functions With Convex Absolute Values of the Second Derivatives via Fractional Integrals”. Ukrains’kyi Matematychnyi Zhurnal 70, no. 12 (December 25, 2018): 1696-1706. Accessed December 2, 2020. http://umj.imath.kiev.ua/index.php/umj/article/view/1668.