1. Requicha A. Representation for rigid solids: theory, methods and systems. ACM Comp Surv. 1980;12(4):437–64.
2. Corbett JP. Topological principles in cartography. Washington, DC: Bureau of the Census, US Department of Commerce; 1979.
3. Härder T. New approaches to object processing in engineering databases. In: Proceedings of the 1986 International Workshop on Object-Oriented Database Systems; 1986.
4. Frank AU, Kuhn W. Cell graph: a provable correct method for the storage of geometry. In: Proceedings of the 2nd International Symposium on Spatial Data Handling; 1986.
5. Alexandrov PS. Combinatorial topology volumes 1, 2 and 3. Mineola/New York: Dover Publications, Inc.; 1960.