Shixiong Zhang,Xiufeng Bao ,Lei Wang. An Economic Optimal Model For Risk Analysis of IT Security[EB/OL]. Beijing:Sciencepaper Online[2004-10-06]. http://www.paper.edu.cn/releasepaper/content/200410-15. 此文件来自 中国科技论文在线 请勿作用于商业用途!