共 12 条
- [11] What Do R & D Numbers Tell Us about Technological Change?[J] . Nestor E. Terleckyj.The American Economic Review . 1980 (2)
- [12] Tests of a Schumpeterian model of R&D and market structure .2 Levin,Richard C,Peter Reiss. R&D, Patents, and Productivity . 1984