8Jagdish Bhagwati, "Growth, Terms of Trade and Comparative Advantage,"Economia Internazionale, no. 12, 1959.
9A. Krueger and H. Sonnensehein, "The Terms of Trade, the Gains from Trade, and Price Divergence, " International Economic Review, vol. 8, no. 1, 1967, pp. 121-127.