Solution and Generalized Hyers-Ulam Stability of a 2-variable Cubic Functional Equation
          Ravi, K.; Kumar, B. V. S.; Thandapani, E; Pinelas, Sandra  
          
          Pan American Mathematical Journal, 20 (2010), 15-30  
          http://www.internationalpubls.com/Journals/index.PanAmerican.pdf  
           
            
         |