Kwang YulSeo, Objects versus Abstract Data Types
It links to two papers by William R. Cook and shortly comments on them. The two papers are: "On Understanding Data Abstraction, Revisited" http://www.cs.utexas.edu/\textasciitilde wcook/Drafts/2009/essay.pdf (on the differences between two forms of data abstraction, objects and abstract data types). and "Object-Oriented Programming Versus Abstract Data Types" https://www.cs.utexas.edu/users/wcook/papers/OOPvsADT/CookOOPvsADT90.pdf (shows why distinguishing these two data abstractions are important).
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