M. Fatih Demirci Ali Shokoufandeh Sven J. Dickinson Yakov Keselman Lars Bretzner Many-to-Many Feature Matching Using Spherical Coding of Directed Graphs. 322-335 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3021&spage=322 2004 conf/eccv/2004-1 ECCV (1) db/conf/eccv/eccv2004-1.html#DemirciSDKB04