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- [3] Mapping evolutionary trajectories: Applications to the growth and transformation of medical knowledge[J] . A. Mina,R. Ramlogan,G. Tampubolon,J.S. Metcalfe.Research Policy . 2007 (5)
- [4] Patent Statistics as Economic Indicators: A Survey[J] . Zvi Griliches.Journal of Economic Literature . 1990 (4)