[1] E.F. Codd:
The Relational Model for Database Management: Version 2. Addison - Wesley Publishing Company 1990.
Zbl 0809.68056
[2] P.C. Kanellakis:
Elements of Relational Database Theory. In: Handbook of Theoretical Computer Science, pp. 1073-1156, Elsevier Science Publishers B.V., 1990.
MR 1127202 |
Zbl 0900.68090
[3] J. Karásek:
On a Modification of Relational Axioms. Archivum Mathematicum Brno, 28 (1992), 95- 111.
MR 1201871
[4] J. Pokorný I. Halaška: Databázové systémy. Skriptum ČVUT, Praha 1995.
[5] J. Šlapal:
Cardinal Arithmetic of General Relational Systems. Czechoslovak Mathematical Journal, 43 (118), 125 - 139, Praha 1993.
MR 1205236
[6] J. Šlapal:
A Note on General Relations. Math. Slovaca, 45 (1995), 1-8.
MR 1335834