共 5 条
- [4] Geographically and technologically mediated knowledge spillovers between European regions[J] . Lydia Greunz.The Annals of Regional Science . 2003 (4)
- [5] ISSUES IN ASSESSING THE CONTRIBUTION OF RESEARCH AND DEVELOPMENT TO PRODUCTIVITY GROWTH [J]. BELL JOURNAL OF ECONOMICS, 1979, 10 (01): : 92 - 116