Data abstraction, data bases and conceptual modelling (Position Paper)

J.W. Thatcher

Journal of Computer and System Sciences

J.W. Thatcher, E.G. Wagner, et al.

ACM Transactions on Programming Languages and Systems (TOPLAS)

J.A. Goguen, J.W. Thatcher, et al.

Journal of the ACM

J.W. Thatcher, J.B. Wright

Mathematical Systems Theory