PečarićJ. E., PerušićA. and SmoljakK. (2015) “Generalizations of Steffensen’s Inequality by Lidstone’s Polynomials”, Ukrains’kyi Matematychnyi Zhurnal, 67(11), pp. 1525-1539. Available at: http://umj.imath.kiev.ua/index.php/umj/article/view/2087 (Accessed: 3December2020).