1.
HEIMLER A, MALERBA F, PERETTO P. Sources, appropriability, and directions of technological change: the cases of the United States and Italy. PSL QR [Internet]. 2013 Oct. 19 [cited 2024 Nov. 23];46(185). Available from: https://rosa.uniroma1.it/rosa04/psl_quarterly_review/article/view/10687