WASET
    Alexander Y. Vaninsky,  Environmental Efficiency of Electric Power Industry of the United States: A Data Envelopment Analysis Approach.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2008, vol. 16(4). 509 - 515
    [viewed 29 March 2024]. Available from: https://publications.waset.org/pdf/8993.