1. Zadeh, L.A.: Fuzzy sets. Inf. Control 8, 338–353 (1965)
2. Yaqoob, N.: Interval-valued intuitionistic fuzzy ideals of regular LA-semigroups. Thai J. Math. 11(3), 683–695 (2013)
3. Yaqoob, N., Khan, M., Akram, M., Khan, A.: Interval valued intuitionistic $$(\overline{S},\overline{T})$$ ( S ¯ , T ¯ ) -fuzzy ideals of ternary semigroups. Indian J. Sci. Technol. 6(11), 5418–5428 (2013)
4. Yaqoob, N., Chinram, R., Ghareeb, A., Aslam, M.: Left almost semigroups characterized by their interval valued fuzzy ideals. Afrika Matematika 24(2), 231–245 (2013)
5. Yaqoob, N., Akram, M., Aslam, M.: Intuitionistic fuzzy soft groups induced by $$(t, s)$$ ( t , s ) -norm. Indian J. Sci. Technol. 6(4), 4282–4289 (2013)