WASET
    Yanshuang Zhang and  Byungho Jeong,  An Output Oriented Super-Efficiency Model for Considering Time Lag Effect.   journal   = {International Journal of Industrial and Manufacturing Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2015, vol. 97(1). 38 - 41
    [viewed 29 March 2024]. Available from: https://publications.waset.org/pdf/10000289.