1. On nonlinear contractions;Boyd,1969
2. Nonlinear Operators and Nonlinear Equations of Evolution in Banach Spaces;Browder,1976
3. On fixed and periodic points under contractive mappings;Edelstein;J. London Math. Soc.,1962
4. A generalization of a fixed point theorem of Reich;Hardy;Canad. Math. Bull.,1973
5. Some results on fixed points, II;Kannan;Amer. Math. Monthly,1969