Yinian Qi Sarvjeet Singh Rahul Shah Sunil Prabhakar Indexing Probabilistic Nearest-Neighbor Threshold Queries. 87-102 2008 QDB/MUD http://www.vldb.org/conf/2008/workshops/WProc_qdbmud/mud4.pdf conf/iqis/2008 db/conf/iqis/qdbmud2008.html#QiSSP08