CeroneP., DragomirS. S., and KikiantyE. “Jensen – Ostrowski Inequalities and Integration schemes via the Darboux Expansion”. Ukrains’kyi Matematychnyi Zhurnal 69, no. 8 (August 25, 2017): 1123-1140. Accessed July 28, 2021. http://umj.imath.kiev.ua/index.php/umj/article/view/1763.