1. S. Abiteboul, N. Bidoit: Non First Normal Form Relations: An Algebra Allowing Data Restructuring, Rapport de Recherche No 347, Institut de Recherche en Informatique et en Automatique, Rocquencourt, France, Nov. 1984
2. M.M. Astrahan et al., System R: Relational Approach to Database Management, ACM TODS, Vol. 1, No. 2 (June 1976)
3. D. Bryce, R. Hull: SNAP: A Graphics-based Schema Manager, Proc. IEEE Intl. Conf. on Data Engineering, Feb. 1986, pp. 151–164
4. H. Boral, et al.: Prototyping Bubba, A Highly Parallel Database System, IEEE TKDE, Vol. 2, No. 1, March 1990, pp. 4–24
5. M.J. Carey, D.J. DeWitt, J.E.Richardson, and E.J.Shekita: Object and File Management in the EXODUS Extensible Database System, Proc. 12th Int. Conf. VLDB, Kyoto, Aug. 1986, pp. 91–100