1. Decision making in a fuzzy environment;Bellmam;Management Science,1970
2. Operations on fuzzy numbers;Dubois;Internat. J. Systems Sci,1976
3. Systems of linear fuzzy constraints;Dubois;Fuzzy sets and Systems,1980
4. Introduction to Approximation Theory;Cheney,1966
5. Applications of Fuzzy sets to Systems Analysis;Negoita,1975