7Battese, G.E., Coelli, T.J., (1995) "A Model for Technical Inefficiency Effects in a Stochastic Fron- tier Production Function for Panel Data," Empirical Economics 20 (2) , 325-332.
8Coelli, T.J., (1996) "A Guide to Frontier Version 4.1: A Computer Program for Stochastic Frontier Production and Cost Function Estimation," CEPA Working Paper.
9Kumbhakar, S.C., (2000) "Estimation and Decomposition of Productivity Change when Production is not Efficient: a Panel Data Approach," Econometric Reviews 19 (4) , 425-460.
10Reifschneider, D., Stevenson, R., (1991) "Systematic Departures from the Frontier: A Framework for the Analysis of Firm Inefficiency," International Economic Review 32 (3) , 715-723.
