Dragomir, S. S., M. V. Boldea, and M. Megan. “Inequalities for Chebyshev Functional in Banach Algebras”. CUBO, A Mathematical Journal 19, no. 1 (March 1, 2017): 53–77. Accessed May 18, 2024. https://www.perspectivasdelacomunicacion.cl/ojs/index.php/cubo/article/view/1143.