1. B. M.Baczynski, Fuzzy implication, Berlin: springer, 2008.
2. B. Schweizer and A. Sklar, Probabilistic Metric Spaces, vol. 2, M. N. Dover Publications, Ed., Amsterdam: North Holland, 1983, p. 275.
3. B.Jayaram, On the law of imprtation in fuzzy logic, IEEE Trans., 2008.
4. D. E. Y.Shi, On the chacterization of fuzzy implications satisfying I(x,y)=I(x,I(x,y)), Inf.Sci, 2007.
5. D.H.Hyers, on the stability of the linear functional equation, USA, 1941.