Thomas Kudrass Tobias Krumbein Rule-Based Generation of XML DTDs from UML Class Diagrams. 339-354 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2798&spage=339 2003 conf/adbis/2003 ADBIS db/conf/adbis/adbis2003.html#KudrassK03