db/conf/gis/GrogerP97.html Gerhard Gröger Lutz Plümer Provably Correct and Complete Transaction Rules for GIS. 40-43 GIS1997/P040.pdf 1997 conf/gis/97 ACM-GIS http://doi.acm.org/10.1145/267825.267837 db/conf/gis/gis97.html#GrogerP97