Zhigeng Fang Sifeng Liu Aiqing Ruan Study on chain structure model of evolutionary game based on asymmetric case. 5818-5823 2004 conf/smc/2004 SMC (6) http://dx.doi.org/10.1109/ICSMC.2004.1401123 db/conf/smc/smc2004-6.html#FangLR04