YANG , G.-S.; LIN, Y.-J. ON COMPANION INEQUALITIES RELATED TO HEINIG’S. Tamkang Journal of Mathematics, [S. l.], v. 22, n. 4, p. 313–322, 1991. DOI: 10.5556/j.tkjm.22.1991.4615. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4615. Acesso em: 4 may. 2024.