Levene, M. (1992). The nested universal relation database model. Springer-Verlag.
Cita Chicago (17th ed.)Levene, M. The Nested Universal Relation Database Model. Berlin ; New York: Springer-Verlag, 1992.
Cita MLA (8th ed.)Levene, M. The Nested Universal Relation Database Model. Springer-Verlag, 1992.
Atenció: Aquestes cites poden no estar 100% correctes.