YANG, G.-S.; HUANG, T.-S. On some inequalities related to Opial-Type inequality in two variables. Tamkang Journal of Mathematics, [S. l.], v. 33, n. 4, p. 379–386, 2002. DOI: 10.5556/j.tkjm.33.2002.287. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/287. Acesso em: 26 apr. 2024.