Gerson Sunyé Damien Pollet Yves Le Traon Jean-Marc Jézéquel Refactoring UML Models. 134-148 2001 conf/uml/2001 UML http://link.springer.de/link/service/series/0558/bibs/2185/21850134.htm db/conf/uml/uml2001.html#SunyePTJ01