References
- Lattice theory G.Birkhoff
- Fuzzy Set and System-Theoty and Application D.Dubois
- Fuzzy Sets and Systems v.30 Fuzzy equivalence relations V.Murail
- Fuzzy Sets and Systems v.19 Fuzzy relations and fuzzy functions W.C.Nemitz
- Fuzzy Sets and Systems v.76 t-fuzzy mapping F.I.Sidky
- Inform and Control v.8 Fuzzy Sets L.A.Zadeh