Aydın, Cafer, and Seher Sultan Yeşilkaya. “A New Approach to Multivalued Certain Contraction Mappings”. Communications in Mathematics and Applications 11, no. 2 (June 30, 2020): 241–252. Accessed July 3, 2024. https://rgnpublications.com/journals/index.php/cma/article/view/1330.