HWANG, D.-Y.; YANG, G.-S. On Ostrowski and Gr"uss type discrete inequalities for second forward differences. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 1, p. 87–93, 2004. DOI: 10.5556/j.tkjm.35.2004.230. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/230. Acesso em: 5 jul. 2022.