School of Mathematics Sciences, Qufu Normal University, Qufu, Shandong 273165, China
Academic Editor: T. Benavides
Copyright © 2011 Xinsheng Du and Zengqin Zhao. 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.
We obtain some new existence and uniqueness theorems of positive fixed point of mixed monotone operators in Banach spaces partially ordered by a cone. Some results are new even for increasing or decreasing operators.