Junhua Zhang Zhiqiu Huang Zining Cao Fangxiong Xiao Counterexample Generation for Probabilistic Timed Automata Model Checking. 210-214 2008 CSSE (2) http://dx.doi.org/10.1109/CSSE.2008.371 conf/csse/2008-2 db/conf/csse/csse2008-2.html#ZhangHCX08