1. Abiteboul,S., N. Bidoit, "Non-First-Normal-Form-Relations to Represent Hierarchically Organized Data", Proc. 3rd. ACM PODS, 1984, and also in Journal of Computer and System Sciences.
2. Abiteboul, S., C. Beeri, "On the Manipulation of Complex Objects", in Proc. International Workshop on Theory and Applications of Nested Relations and Complex Objects, Darmstadt, 1987.
3. Abiteboul S., S. Ginsburg, "Tuple Sequences and Lexicographical Indexes", JACM, 33, 1986.
4. Abiteboul, S., S. Grumbach, "A Logical Approach to the Manipulation of Complex Objects", in Proc. International Workshop on Theory and Applications of Nested Relations and Complex Objects, Darmstadt, 1987.
5. Lectures Notes in Computer Science;S. Abiteboul,1988