Ming-Chih Hsu Paul Hsueh-Min Chang Yi-Ming Wang Von-Wun Soo Multi-agent Travel Planning through Coalition and Negotiation in an Auction. 62-73 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2891&spage=62 2003 conf/prima/2003 PRIMA db/conf/prima/prima2003.html#HsuCWS03