1. M. Bloemmen, A. Ligtenberg, R. van Lammeren, T. Hoogerwerf. “Approaches for the use of geo-visualisation in participatory planning processes—version 7.” PSPE project publication, Wageningen University, 2005, p. 26.
2. L.L. Boyd. “CDM RuleFrame—the business rule implementation framework that saves you work”. Oracle Corporation, iDevelopment Center of Excellence, ODTUG Business Rules Symposium, 2001.
3. E. Clementini, P. Di Felice, and P. van Oosterom. “A small set of formal topological relationships suitable for end-user interaction,” in SSD’93 (Ed.), Third International Symposium on Large Spatial Databases, Singapore, LNCS No. 692, Springer: Berlin Heidelberg New York, 277–295, 1993.
4. S. Cockcroft. “A taxonomy of spatial data integrity constraints,” GeoInformatica, Vol. 1(4):327–343, 1997.
5. S. Cockcroft. “The design and implementation of a repository for the management of spatial data integrity constraints,” GeoInformatica, Vol. 8(1):49–69, 2004.