1. Allen, J.F. (1984), Towards a general theory of action and time. Artificial Intelligence 23. 123–154.
2. Brachman, R.J. (1977), What’s in a concept: structural foundations for semantic networks. International Journal of Man-Machine Studies 9. 127–152.
3. Clarke, B.L. (1981), A calculus of individuals based on ‘connection’. Notre Dame Journal of Formal Logic 22. 204–218.
4. Comrie, B. (1976), Aspect. Cambridge: Cambridge University Press.
5. Egenhofer, M.J. (1991), Reasoning about binary topological relations. In O. Günther & H.-J. Schek (eds.), Advances in Spatial Databases (pp. 143-160). New York, NY: Springer.