TY  - BOOK
AU  - Codd,E.F.
TI  -  The relational model for database management: version 2 
SN  - 0201141922
AV  - QA 76.9 .D3C62 1990
PY  - 1990///
CY  - New York
PB  - Addison-Wesley
KW  - Database management
KW  - Relational databases
N1  - Includes bibliographical references (p. 505-510) and index
ER  -