TY  - BOOK
AU  - Codd, E F 
TI  - Relational model for database management: : version 2
SN  - 0-201-14192-2
PY  - 1990///
CY  - New York: 
PB  - Addison- Wesley Publishing Company,  
KW  - General management
KW  - Database management
ER  -