Universes of Fuzzy Sets and Axiomatizations of Fuzzy Set Theory. Part I: Model-Based and Axiomatic Approaches.

Siegfried Gottwald Universes of Fuzzy Sets and Axiomatizations of Fuzzy Set Theory. Part I: Model-Based and Axiomatic Approaches. 211-244 2006 82 Studia Logica 2 http://dx.doi.org/10.1007/s11225-006-7197-8 db/journals/sLogica/sLogica82.html#Gottwald06