PACHPATTE, B. G. OPIAL TYPE INEQUALITY IN SEVERAL VARIABLES. Tamkang Journal of Mathematics, [S. l.], v. 22, n. 1, p. 7–11, 1991. DOI: 10.5556/j.tkjm.22.1991.4562. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4562. Acesso em: 29 mar. 2024.