Kim Guldstrand Larsen Marius Mikucionis Brian Nielsen Online Testing of Real-time Systems Using Uppaal. 79-94 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3395&spage=79 2004 conf/fates/2004 FATES db/conf/fates/fates2004.html#LarsenMN04