Chumpungam, D., and A. Kettapun. “STABILITY AND RATE OF CONVERGENCE OF SOME ITERATION METHODS FOR BERINDE CONTRACTIONS”. Journal of Nonlinear Analysis and Optimization: Theory & Applications (JNAO), vol. 10, no. 1, Mar. 2019, pp. 21-34, https://ph03.tci-thaijo.org/index.php/jnao/article/view/2841.