PACHPATTE, B. G. A note on Ostrowski and Gr"uss type discrete inequalities. Tamkang Journal of Mathematics, [S. l.], v. 35, n. 1, p. 61–66, 2004. DOI: 10.5556/j.tkjm.35.2004.227. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/227. Acesso em: 26 apr. 2024.