1. Allen, J.F. Towards a General Theory of Action and Time. Artificial Intelligence 23(2): 123–154, 1984.
2. Bobrow, D.G. Qualitative Reasoning About Physical Systems. MIT Press, 1985.
3. Bobrow, D., and Winograd, T. KRL: Knowledge Representation Language. Cognitive Science 1(1), 1977.
4. Brachman, R.J. A Structural Paradigm for Representing Knowledge. PhD thesis, Harvard University, 1977.
5. Brachman, R.J. On the Epistemological Status of Semantic Networks. Associative Networks: Representation and Use of Knowledge by Computers. In Findler, N.V., Academic Press, 1979, pages 3–50.