Cohen, W. M., Nelson, R. R., & Walsh, J. P. (2000). Protecting their intellectual assets: Appropriability conditions and why U.S. manufacturing firms patent(or not). National Bureau of Economic Research.
Lua i Stíl Chicago (17ú heag.)Cohen, Wesley M., Richard R. Nelson, agus John P. Walsh. Protecting Their Intellectual Assets: Appropriability Conditions and Why U.S. Manufacturing Firms Patent(or Not). Cambridge: National Bureau of Economic Research, 2000.
Lua MLA (9ú heag.)Cohen, Wesley M., et al. Protecting Their Intellectual Assets: Appropriability Conditions and Why U.S. Manufacturing Firms Patent(or Not). National Bureau of Economic Research, 2000.
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