Edward Hung Yu Deng V. S. Subrahmanian TOSS: An Extension of TAX with Ontologies and Similarity Queries. 2004 conf/sigmod/2004 SIGMOD Conference db/conf/sigmod/sigmod2004.html#HungDS04 719-730 http://doi.acm.org/10.1145/1007568.1007649 http://www.sigmod.org/sigmod/sigmod04/eproceedings/pdf/R-515.pdf