Fabrizio Falchi Claudio Lucchese Salvatore Orlando Raffaele Perego Fausto Rabitti A metric cache for similarity search. 43-50 2008 LSDS-IR http://doi.acm.org/10.1145/1458469.1458473 conf/cikm/2008lsdsir db/conf/cikm/lsdsir2008.html#FalchiLOPR08