Dong Xu Huaikou Miao Nduwimfura Philbert Model Checking UML Activity Diagrams in FDR. 1035-1040 2009 ACIS-ICIS http://dx.doi.org/10.1109/ICIS.2009.107 conf/ACISicis/2009 db/conf/ACISicis/ACISicis2009.html#XuMP09