Charnes A, WW Cooper, LM Seiford and J Stutz (1983). “Invariant Multiplicative Efficiency and Piecewise Cobb-Douglas Envelopments.” Operations Research Letters 2(3): 101-103.
Charnes A, WW Cooper, LM Seiford and J Stutz (1983). “Invariant Multiplicative Efficiency and Piecewise Cobb-Douglas Envelopments.” Operations Research Letters 2(3): 101-103.