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- [23] Technological Opportunity and Spillovers of R & D: Evidence from Firms' Patents, Profits, and Market Value[J] . Adam B. Jaffe.The American Economic Review . 1986 (5)
- [24] ISSUES IN ASSESSING THE CONTRIBUTION OF RESEARCH AND DEVELOPMENT TO PRODUCTIVITY GROWTH [J]. BELL JOURNAL OF ECONOMICS, 1979, 10 (01): : 92 - 116