Xiaoju Dong Yuxi Fu Observing Asymmetry and Mismatch. 2-19 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2895&spage=2 2003 conf/aplas/2003 APLAS db/conf/aplas/aplas2003.html#DongF03