Douglas Burdick AnHai Doan Raghu Ramakrishnan Shivakumar Vaithyanathan OLAP over Imprecise Data with Domain Constraints. 39-50 2007 conf/vldb/2007 VLDB http://www.vldb.org/conf/2007/papers/research/p39-burdick.pdf db/conf/vldb/vldb2007.html#BurdickDRV07