Copyright © 2011 N. Hussain et al. This is an open access article distributed under the
Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Using the concept of a mixed g-monotone mapping, we prove some coupled coincidence and coupled common
fixed point theorems for nonlinear contractive mappings in partially ordered complete quasi-metric spaces with a
Q-function q. The presented theorems are generalizations of the recent coupled fixed point theorems due to Bhaskar
and Lakshmikantham (2006), Lakshmikantham and Ćirić (2009) and many others.