1. On some logical connectives for fuzzy sets theory;Alsina;J. Math. Ann. Appl.,1983
2. Intuitionistic fuzzy sets;Atanassov;Fuzzy Sets and Systems,1986
3. Review and new results on intuitionistic fuzzy sets;Atanassov;IM-MFAIS,1988
4. Two operators on intuitionistic fuzzy sets, Comptes rendus de l'Académi bulgare des Sciences;Atanassov;Tome,1988
5. On the analytic formalism of the theory of fuzzy sets;Bellman;Inform. Sci.,1973