Jörg H. Siekmann Christoph Benzmüller Omega: Computer Supported Mathematics. 3-28 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3238&spage=3 2004 conf/ki/2004 KI db/conf/ki/ki2004.html#SiekmannB04