CHARNES, A. Programming With Linear Fractional Functions. Naval Research Logistics Quarterly. 1962, 9, 3&4, 181-186
COOPER, W. W. Data Envelopment Analysis. 2000
COTTRELL, T. Software variety and hardware value-a case study of complementary network externalities in the microcomputer software industry. Journal of Engineering and Technology Management. 1998, 15, 4, 309-338
ECONOMIDES, N. Desirability of Compatibility in the Absence of Network Externalities. The American Economic Review. 1989, 79, 5, 1165-1181