1. ANSI/X3/SPARC, Study Group on Data Base Management Systems: Interim Report 75-02-08. ACM SIGMOD Newsletter, 1975. 7(2).
2. Abrial, J.R.: Data Semantics. In: Data Base Management, ed. Klimbie J.W., Koffeman, K.L. (North Holland/Elsevier. 1974). pp 1–69.
3. Berild, S., Nachmens, S.: CS4 a Tool for Database Design by Infological Simulation. In: 3rd International Conference on Very Large Data Bases (Tokyo 1977)
4. Brodie, M.L., Zilles, S. N. (eds): Proceedings of Workshop on Data Abstraction, Databases, and Conceptual Modelling. 1981, ACM SIGMOD Record, Vol. 11, No. 2, Feb. (1981)
5. Bubenko, J.A., Jr.: The Temporal Dimension in Information Modelling. In: IFIP WG 2.6 Working Conference on Architecture and Models in Data Base Management Systems. Nice, France: (North Holland, 1977).