1. Extension principles and fuzzy set categories;He;Computers Math. Applic.,2000
2. A Łukasiewicz logic based prolog;Klawonn;Mathware & Soft Comp.,1994
3. A categorial unification algorithm;Rydeheard,1986
4. Set functors and generalised terms;Eklund;Proc. of IPMU 2000, Information Processing and Management of Uncertainty in Knowledge-Based Systems,2000
5. L-fuzzy sets;Goguen;J. Math. Anal. Appl.,1967