Geng Liang Sim Kim Lau Towards More Flexible Internal Workflow Change: Weakly Equivalence Concept for Inter-organizational Workflow Design. 141-148 2007 conf/wecwis/2007 CEC/EEE http://doi.ieeecomputersociety.org/10.1109/CEC-EEE.2007.101 db/conf/wecwis/cec2007.html#LiangL07