[1] J.A.Schumpeter.Capitalism Socialism and Democracy[M]. Johns Hopkins University Press.1993:152. [2] Kenneth J.Arrow.Economic welfare and the allocation of resource for invention. in:The Rate and Direction of Incentive Activity:Economic and Social Factor.Princeton University Press.1962:609-624. [3] Dasgupta, J.Stigliz. Uncertainty, industrial structure and the speed of R&D [J]. Bell Journal of Economics. 1980( 11):1-28. [4] Loury, G.C. Market structure and the nature of innovation activity[J]. Quarterly Journal of Economics.1979(93): 395-410. [5] Reinganum, J.F. The timing of innovation:research, development, and diffusion. in: Schmalensee, R. & Willig, R. Handbook of Industrial Organization. North-Holland.1989: 852-908. [6] Reinganum, J.F. A Dynamic game of R and D: patent protection and competitive behavior[J]. Econometrica.1982( 50): 671-688. [7] Harris, C. & Vickers, J. Perfect equilibrium in a model of a race[J]. Review of Economic Studies.1985( 2): 193-209. [8] Fudenberg, et al. Preemption, leafrogging, and competition in patent races[J]. European Economic Review.1983 (22): 3-31. [9] Gallini, N.T. & Winter, R.A. licensing in the theory of innovation[J]. Rand Journal of Economics.1985( 16): 237-252. [10] M.L.Katz,C.Shapiro.R and D rivalry with licensing or innovation[J]. American Economics Review. 1987 (77):402-20. [11] Yi, S. Entry, Licensing and research joint ventures[J].International Journal of Industrial Organization.1999 (17): 1-24. [12] Boivin, C. & Langinier, C. Technology licensing to a rival[J].Economics Bulletin.2005 (12): 1-8.