1. Anderson JR, Bower GH. Human associative memory. Washington, DC: V. H. Winston & Sons; 1973.
2. Chen PP. The entity-relationship model – toward a unified view of data. ACM Trans Database Syst. 1976;1(1):9–36.
3. Elmasri R, Wuu G, Kouramajian V. A temporal model and query language for EER databases. In: Tansel A, editor. Temporal databases: theory, design and implementation. Menlo Park: Benjamin/Cummings; 1993. p. 212–29.
4. Ferg S. Modeling the time dimension in an entity-relationship diagram. In: Proceedings of the 4th International Conference on Entity-Relationship Approach; 1985. p. 280–6.
5. Gregersen H, Jensen C. Conceptual modeling of time-varying information. TIMECENTER Technical Report TR-35, Sept 10, 1998.