Feng Qiu Ye Zhao Zhe Fan Xiaoming Wei Haik Lorenz Jianning Wang Suzanne Yoakum-Stover Arie E. Kaufman Klaus Mueller Dispersion Simulation and Visualization For Urban Security. 553-560 2004 conf/visualization/2004 IEEE Visualization http://csdl.computer.org/dl/proceedings/vis/2004/8788/00/87880553.pdf db/conf/visualization/visualization2004.html#QiuZFWLWYKM04