Mınak, Gülhan, and Ishak Altun. “On the Effect of Alpha-Admissibility and Theta-Contractivity to the Existence of Fixed Points of Multivalued Mappings”. Nonlinear Analysis: Modelling and Control, vol. 21, no. 5, Sept. 2016, pp. 673-86, https://doi.org/10.15388/NA.2016.5.7.