R. A. Rashwan, and S. M. Saleh. “Some Common Fixed Point Theorems for Four $(\psi,\varphi)$-Weakly Contractive Mappings Satisfying Rational Expressions in Ordered Partial Metric Spaces”. International Journal of Mathematics And its Applications 2, no. 3 (September 15, 2014): 29–51. Accessed March 28, 2024. http://ijmaa.in/index.php/ijmaa/article/view/309.