DRAGOMIR, S. S. Better bounds in some Ostrowski-Gruss type inequalities. Tamkang Journal of Mathematics, [S. l.], v. 32, n. 3, p. 211–216, 2001. DOI: 10.5556/j.tkjm.32.2001.376. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/376. Acesso em: 18 aug. 2022.