PACHPATTE, B. G. On a new Ostrowski type inequality in two independent variables. Tamkang Journal of Mathematics, [S. l.], v. 32, n. 1, p. 45–49, 2001. DOI: 10.5556/j.tkjm.32.2001.367. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/367. Acesso em: 28 mar. 2024.