6Charnes A, Cooper W W, Rhodes E. Measuring the Efficiency of Decision Making Units [J]. European Journal of Operational Research, 1978, 2 (6): 429-444 .
7Aigner D, Lovell C A K, Schmidt P. Formulation and Estima- tion of Stochastic Frontier Production Function Models [ J]. Journal of E- conometrics, 1977, 6 (1): 21-37 .
8Meeusen W, Broeck J V D. Efficiency Estimation from Cobb- Douglas Production Fmlctions with Composed Error [ J]. Intemational E- conomic Review, 1977, 18 (2): 435-444.