Two Views of Data Abstraction

CACM June, 1977

Ledgard, H. F.
Taylor, R. W.

CA770603 JB December 29, 1977  1:28 AM

2960	5	2960
2960	5	2960
2960	5	2960
3049	5	2960
2956	6	2960
2958	6	2960
2957	6	2960
2960	6	2960