1. Fuzzy sets, fuzzy proofs and certain unsolved problems in the theory of automatic control;Aizerman;Avtomatika i Telemehanika,1976
2. Human Associative Memory;Anderson,1973
3. Fuzzy punctuation or the continuum of grammaticality;Ballmer,1976
4. Language and Information;Bar-Hillel,1964
5. Degree Words;Bellinger,1972