MACHLUP, F. The transfer gap of the United States. PSL Quarterly Review, [S. l.], v. 21, n. 86, 2014. DOI: 10.13133/2037-3643/11717. Disponível em: https://rosa.uniroma1.it/rosa04/psl_quarterly_review/article/view/11717. Acesso em: 30 apr. 2025.