title: a prototype content-based retrieval system that uses virtual images to save space. authors: leonard brown , le gruenwald. venue: vldb. year: 2001
title: spire : a progressive content-based spatial image retrieval engine. authors: chung-sheng li , lawrence d. bergman , yuan-chi chang , vittorio castelli , john r. smith. venue: international conference on management of data. year: 2000