Yibing Song Yongtian Yang Modeling Organization of Multi-Agent System with Command Mechanism. 732-736 2006 conf/imsccs/2006-1 IMSCCS (1) http://doi.ieeecomputersociety.org/10.1109/IMSCCS.2006.89 db/conf/imsccs/imsccs2006-1.html#SongY06