Osamu Takaki Takahiro Seino Izumi Takeuti Noriaki Izumi Koichi Takahashi Verification Algorithm of Evidence Life Cycles in Extended UML Activity Diagrams. 9 2007 ICSEA http://doi.ieeecomputersociety.org/10.1109/ICSEA.2007.84 conf/icsea/2007 db/conf/icsea/icsea2007.html#TakakiSTIT07