Bagul, Yogesh J., and Christophe Chesneau. “Some New Simple Inequalities Involving Exponential, Trigonometric and Hyperbolic Functions”. CUBO, A Mathematical Journal 21, no. 1 (April 1, 2019): 21–35. Accessed October 11, 2025. https://cubo.ufro.cl/index.php/cubo/article/view/2116.