Avrim Blum Jeffrey C. Jackson Tuomas Sandholm Martin Zinkevich Preference Elicitation and Query Learning. 13-25 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2777&spage=13 2003 conf/colt/2003 COLT db/conf/colt/colt2003.html#BlumJSZ03