Alsaleh, M. ., and A. Abdul-Rahim. “Cost Efficiency of Bioenergy Industry and Its Economic Determinants in EU-28: A Tobit Model Based on DEA Efficiency Scores”. International Journal of Management and Sustainability, vol. 8, no. 2, June 2019, pp. 79-87, doi:10.18488/journal.11.2019.82.79.87.