Hummels, David, Jun Ishii and Kei-Mu Yi (1998). Vertical specialization and the changing nature of world trade. Economic Policy Review (Federal Reserve Bank of New York), pp. 79-99, June.
Hummels, David, Jun Ishii and Kei-Mu Yi (1998). Vertical specialization and the changing nature of world trade. Economic Policy Review (Federal Reserve Bank of New York), pp. 79-99, June.