Stefan Jurack Leen Lambers Katharina Mehner Gabriele Taentzer Gerd Wierse Object Flow Definition for Refined Activity Diagrams. 49-63 2009 FASE http://dx.doi.org/10.1007/978-3-642-00593-0_4 conf/fase/2009 db/conf/fase/fase2009.html#JurackLMTW09