Bernard J, U Cantner and G Westermann (1996). “Technological Leadership and Variety: A Data Envelopment Analysis for the French Machinery Industry.” Ann Oper Res 68: 361-377.
Bernard J, U Cantner and G Westermann (1996). “Technological Leadership and Variety: A Data Envelopment Analysis for the French Machinery Industry.” Ann Oper Res 68: 361-377.