1. Fuzzy cyclic subgroups and fuzzy cyclic p-subgroups;Alkhamees;J. Fuzzy Math.,1995
2. Fuzzy Sets Fuzzy Methods Fuzzy Logic with Applications;Bandemer,1995
3. Lattice Theory;Birkhoff,1967
4. Introduction to Lattices and Order;Davey,1992
5. L-fuzzy Sets;Goguen;J. Math. Anal. Appl.,1967