Ghassan Beydoun John K. Debenham Achim G. Hoffmann Using Messaging Structure to Evolve Agents Roles in Electronic Markets. 18-28 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3371&spage=18 2004 conf/prima/2004 PRIMA db/conf/prima/prima2004.html#BeydounDH04