1. Allen, J. F. (1983). Maintaining knowledge about temporal intervals. Communications of the ACM, 26(11), 832–843.
2. Clementini, E. and Di Felice, P. (1995). A comparison of methods for representing topological relationships. Information Sciences. To appear.
3. Clementini, E., Di Felice, P., and Hernández, D. (1995). Qualitative representation of positional information. In preparation.
4. Clementini, E., Di Felice, P., and van Oosterom, P. (1993). A small set of formal topological relationships suitable for end-user interaction. In Abel, D. and Ooi, B. C., editors, Third International Symposium on Large Spatial Databases, SSD '93, Volume 692 of Lecture Notes in Computer Science, pages 277–295. Springer, Berlin.
5. Egenhofer, M. J. and Franzosa, R. (1991). Point-set topological spatial relations. International Journal of Geographical Information Systems, 5(2), 161–174.