TY  - BOOK
AU  - Symposium on Mathematical Fundamentals of Database Systems ( 2nd
AU  - Demetrovics,J.,ed. Thalheim,B.,ed.
TI  - MFDBS '89
T2  - Lecture notes in computer science
SN  - 3540512519
U1  - 001.6442 
PY  - 1989///
CY  - Berlin
PB  - Springer-Verlag
ER  -