Altun, Ishak, Gülhan Mınak, and Murat Olgun. “Fixed Points of Multivalued Nonlinear F-Contractions on Complete Metric Spaces”. Nonlinear Analysis: Modelling and Control 21, no. 2 (March 25, 2016): 201–210. Accessed May 9, 2024. https://www.journals.vu.lt/nonlinear-analysis/article/view/13483.