5Wei David Zhang,Shuo Zhang,Xueming Luo.??Technological progress, inefficiency, and productivity growth in the US securities industry, 1980–2000(J)Journal of Business Research . 2005 (5)
6K. -L. Wang,Y. -T. Tseng,C. -C. Weng.??A study of production efficiencies of integrated securities firms in Taiwan(J)Applied Financial Economics . 2003 (3)