Reynold Cheng Lei Chen 0002 Jinchuan Chen Xike Xie Evaluating probability threshold k-nearest-neighbor queries over uncertain data. 672-683 2009 EDBT http://doi.acm.org/10.1145/1516360.1516438 conf/edbt/2009 db/conf/edbt/edbt2009.html#ChengCCX09