Grosskopf S, K Hayes and S Yaisawarng (1992). “Measuring Economies of Diversification – a Frontier Approach.” J Business and Economic Statistics 1: 453-459.
Grosskopf S, K Hayes and S Yaisawarng (1992). “Measuring Economies of Diversification – a Frontier Approach.” J Business and Economic Statistics 1: 453-459.