1. H. Aktaş, N. Çağman, Soft sets and soft groups, Information Sciences, in press, doi:10.1016/j.ins.2006.12.008.
2. K.T. Atanassov, Intuitionistic fuzzy sets, 1983, VII ITKR’s Session, Sofia (deposed in Central Sci. Technical Library of Bulg. Acad. of Sci., 1697/84) (in Bulgarian).
3. Intuitionistic fuzzy sets;Atanassov;Fuzzy Sets and Systems,1986
4. Intuitionistic Fuzzy Sets;Atanassov,1999
5. Triangular norm-based intuitionistic fuzzy propositional calculus;Atanassov;Notes on Intuitionistic Fuzzy Sets,2001