Walid G. Aref Mohamed F. Mokbel Markus Schneider 0001 16th ACM SIGSPATIAL International Symposium on Advances in Geographic Information Systems, ACM-GIS 2008, November 5-7, 2008, Irvine, California, USA, Proceedings 978-1-60558-323-5 GIS ACM 2008 db/conf/gis/gis2008.html