Jagan Sankaranarayanan Egemen Tanin Hanan Samet Frantisek Brabec Accessing Diverse Geo-Referenced Data Sources with the SAND Spatial DBMS. 2003 DG.O http://diggov.org/dgrc/dgo2003/cdrom/DEMOS/sankaranarayanan.pdf db/conf/dgo/dgo2003.html#SankaranarayananTSB03