TY  - BOOK
AU  - Polkowski, Lech
TI  - Rough sets Mathematical foundations
SN  - 3790815101
U1  - 511.32 POL/R 
PY  - 2002///
CY  - Heidelberg
PB  - Physica-Verlag
KW  - MATHEMATICS
KW  - SET THEORY
ER  -