Albano, A., Giannotti, F., Orsini, R., AND Pedreschi, D. The type system of Gallleo.

Data Types and Persistence. (1988) Data Types and Persistence. Atkinson, MP, Buneman, OP, Morrison, R (eds), Proc. 1st Workshop on Persistent Object Systems, Appin, Scotland, 1985. In Series: Topics in Information Systems. Springer-Verlag, ISBN 3-540-18785-5. 1988  

Languages mentioned Galileo {1983} interactive, strictly-typed data base programming language