Zweerink, G. H. "SEVAL, A High-Level Validation Language". pp154-172

(1981) "Trends in Information Processing Systems, 3rd Conference of the European Cooperation in Informatics", Munich, Germany, October 20-22, 1981, A. J. W. Duijvestijn, Peter C. Lockemann (Eds.): Lecture Notes in Computer Science 123 Springer 1981  

Languages mentioned SEVAL {1981} Data validation language