Furtado, A.L. Veloso, P.A.S. and Casanova, M.A. "A Grammatical Approach to Data Bases" pp705-710

Mason, R. (1983) Mason, R. E. A. (Ed.): Information Processing 83, Proceedings of the IFIP 9th World Computer Congress, Paris, France, September 19-23, 1983. North-Holland/IFIP, 1983,  

Languages mentioned DDL {1980} Data definition language DML {1980}