Zhang," Deng Hua",cao," Huai Xin, Stability of Functional Equations in Several Variables, Acta mathematica Sinica. English series (Print) , 23(2), 2007, pp. 321-326
In this note, we prove a generalization of Hyers. theorem on the stability of approximately additive mapping and a generalization of Badora.s theorem on an approximate ring homomorphism. We also obtain a more general stability theorem, which gives the stability theorems on Jordan and Lie homomorphisms. The proofs of the theorems given in this paper follow essentially the D. H. Hyers-Th. M. Rassias approach to the stability of functional equations connected with S. M. Ulam.s problem.