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Spillovers, rivalry and R&D investment
Goel, Rajeev K., (1995)
Innovation and industry bifurcation : the evolution of R&D strategy
Lee, Jeho, (2001)
Firm heterogeneity, imitation, and the incentives for cost reducing R&D effort
Ceccagnoli, Marco, (2003)
Imitation Costs and Patents: An Empirical Study.
Mansfield, Edwin, (1981)
Imitation costs and patents : an empirical study
Patents, imitation costs, and the rate of innovation
Mansfield, Edwin, (1982)