Common fixed point theorems for Ciric type mappings in b-metric spaces without any completeness assumption

In this paper, we establish some common fixed point theorems for four mappings satisfying Ciric type contractive condition in b-metric spaces without any completeness assumption. Our results improve and generalize the results in the very recent papers ([Z.-Z. Yang, H. Sadati, S. Sedghi, N. Shobe, J. Nonlinear Sci. Appl., 8 (2015), 1022–1031], [V. Ozturk, S. Radenovic´, SpringerPlus, 5 (2016), 10 pages]). Particularly, the contractive constant k/b² in the result of Yang et al. is enlarged to k/b . Some examples are provided to support our results.