Alfredo Cuzzocrea Wei Wang Ugo Matrangolo Answering Approximate Range Aggregate Queries on OLAP Data Cubes with Probabilistic Guarantees. 97-108 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3181&spage=97 2004 conf/dawak/2004 DaWaK db/conf/dawak/dawak2004.html#CuzzocreaWM04