Common fixed points of Ćirić-type contractions on partial metric spaces

We obtain a common fixed point theorem of Boyd{Wong type for four mappings satisfying a ćirić-type contraction on a complete partial metric space. Our result generalizes and unifies, among others, the very recent results of L. ćirić, B. Samet, H. Aydi and C. Vetro [Common fixed points of generalized contractions on partial metric spaces and an application, Appl. Math. Comput., 218 (2011), 2398-2406], S. Romaguera [Fixed point theorems for generalized contractions on partial metric spaces, Topology Appl., 159 (2012), 194-199], T. Abdeljawad, E. Karapinar and K. Tas [Existence and uniqueness of a common fixed point on partial metric spaces, Appl. Math. Lett. 24 (2011), 1900-1904], and D. Ilić, V. Pavlović and V. Rakoč ević [Some new extensions of Banach's contraction principle to partial metric space, Appl. Math. Lett. 24 (2011), 1326{1330].