Sokhanvar,M , , Sadeghi,H , , Assari,A , , Yavari,K , and naderan,E . "Determinating the Efficiency of Electricity Distribution Companies of Iran and Factors Affecting it By Using Data Envelopement Analysis and Two - Stage Approach", Journal of Economic Research (Tahghighat- E- Eghtesadi), 47, 2, 2012, 21-39. doi: 10.22059/jte.2012.25008