%0 Journal Article %T FORTI’S APPROACH IN FIXED POINT THEORY AND THE STABILITY OF A FUNCTIONAL EQUATION ON METRIC AND ULTRA METRIC SPACES %A Rahbarnia, Freydoon %A TH. M. RASSIAS %A Reaz Saadati %A Ghadir Sadeghi %J Journal of Computational Analysis and Applications %@ 1521-1398 %D 2011