Serge Abiteboul, Richard Hull. Data Functions, Datalog and Negation (Extended Abstract). In Haran Boral, Per-Åke Larson, editors, Proceedings of the 1988 ACM SIGMOD International Conference on Management of Data, Chicago, Illinois, June 1-3, 1988. pages 143-153, ACM Press, 1988. [doi]
Abstract is missing.