Martin Raubal Harvey J. Miller Andrew U. Frank Michael F. Goodchild Geographic Information Science, 4th International Conference, GIScience 2006, Münster, Germany, September 20-23, 2006, Proceedings GIScience Lecture Notes in Computer Science 4197 Springer 2006 3-540-44526-9 db/conf/giscience/giscience2006.html