1. Altrock, C.: Fuzzy Logic and NeuroFuzzy Applications Explained. Prentice Hall PTR, Englewood Cliffs (1995)
2. Buckles, B.P.: An information retrieval perspective on fuzzy database systems. In: Proceedings of the ACM 1982 conference, pp. 186–187 (1982) ISBN:0-89791-085-0
3. Elmasri, R., Navathe, S.: Fundamentals of Database Systems. 3rd edn. Addison Wesley, Reading (2000) ISBN 9814053309
4. Kwan, S., Olken, F., Rotem, D.: Uncertain, Incomplete and Inconsistent Data in Scinetific and Statistical Databases. Uncertainty Management in Information Systems, 127–154 (1996)
5. Mendel, J.M.: Fuzzy logic systems for engineering: a tutorial. Proceedings of the IEEE 83(3), 345–377 (1995)