Coupled fixed point theorems for nonlinear contractions in partially ordered GG-metric spaces

We prove coupled coincidence and coupled common fixed point theorems for a mixedgg-monotone mapping satisfying nonlinear contractions in partially ordered GG-metric spaces. Presented theorems are generalizations of the very recent results of Choudhury and Maity [B.S. Choudhury, P. Maity, Coupled fixed point results in generalized metric spaces, Math. Comput. Modelling 54 (1–2) (2011) 73–79].