1. R&D Spillovers and Recipient Firm Size;Z J Acs;Review of Economics and Statistics,1994
2. Productivity Differences among Scientists: Evidence for Accumulative Advantage;P D Allison;American Sociological Review,1974
3. Economic welfare and the allocation of resources for invention;K Arrow;The rate and direction of inventive activity: economic and social factors,1962
4. R&D Spillovers and the Geography of Innovation and Production;D B Audretsch;American Economic Review,1996