1. Fuzzy sets as a basis for a theory of possibility;Zadeh;Fuzzy Sets and Systems,1977
2. Some mathematical tools for linguistic probabilities;Nguyen,1977
3. Local and fuzzy logics;Bellman,1977
4. A Mathematical Theory of Evidence;Shafer,1976
5. Mesure de l'information fournie par un événement;Kampe de Feriet;Coll. Inter. C.N.R.S. Paris,1970