1. [AB88] Abiteboul, S., Beeri, C.: On the power of languages for the manipulation of complex objects. Technical Report No. 846, INRIA, May 1988
2. [AGSS86] Aylamazyan, A.K., Gilula, M.M., Stolboushkin, A.P., Schwartz, G.F.: Reduction of the relational model with infinite domain to the case of finite domains (Russian). Proc. USSR Acad. Sci. (Doklady)286(2), 308?311 (1986)
3. [AV87] Abiteboul, S., Vianu, V.: A transaction language complete for database update and specification. Proceedings of the ACM Symposium on Principles of Database Systems, pp. 260?268, 1987
4. [CH80] Chandra, A.K., Harel, D.: Computable queries for relational data bases. J. Comput. Syst. Sci.,21(2), 156?178 (1980)
5. [Cod70] Codd, E.F.: A relational model of data for large shared data banks. Commun. ACM13(6), 377?387 (1970)