References
- E.F. Codd , “A Relational Model of Data for Large Shared Data Banks,” Communications of the CACM 13 ( June 1970 ).
- E.F. Codd , “Extending the Relational Model to Capture More Meaning,” Transactions on Data Base Systems 4 ( December 1979 ).
- C.J. Date , An Introduction to Database Systems , 4th ed ( Reading MA AddiaorvWesley . 1986 ).
- E.F. Codd , “Is Your DBMS Really Relational?” Compute/world ( October 14 , 1985 ), In-Depth section pp 1 – 9 .