Antonacci, F. et al "AQL: A Relational Database Management System and Its Geographical Applications" pp569-599

[Proceedings] (1980) Blaser, Albrecht (Ed.) Proceedings og the Conference on Data Base Techniques for Pictorial Applications, Florence, Italy, June 20-22, 1979, LNCS 81 Springer 1980, ISBN 3-540-09763-5  

Languages mentioned AQL {1977} APL with picture primitives