TY  - BOOK
AU  - Zimmermann, H.-J. 
TI  - Fuzzy set theory: and its applications 
SN  - 9789401038706
U1  - 511.3 4th ed.
PY  - 2001///
CY  - New York
PB  - Springer Science + Business Media
KW  - Fuzzy sets.
KW  - Operations research
N1  - includes bibliographical references
ER  -