Claudia Fritsch Burkhardt Renz Four Mechanisms for Adaptable Systems: A Meta-level Approach to Building a Software Product Line. 51-72 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3154&spage=51 2004 conf/splc/2004 SPLC db/conf/splc/splc2004.html#FritschR04