Luo Si Jamie Callan The Effect of Database Size Distribution on Resource Selection Algorithms. 31-42 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2924&spage=31 2003 conf/sigir/2003dmir Distributed Multimedia Information Retrieval db/conf/sigir/sigir2003dmir.html#SiC03a