Ampadu, Clement Boateng. “The Convex (δ, L) Weak Contraction Mapping Theorem and Its Non Self Counterpart in Graphic Language ”. Earthline Journal of Mathematical Sciences 1, no. 2 (February 26, 2019): 157-169. Accessed June 29, 2025. https://www.earthlinepublishers.com/index.php/ejms/article/view/89.