1. Baldwin, Robert E., “Determinants of the Commodity Structure of U.S. Trade”.The American Economic Review, Vol. 61, 1971, pp. 126–146.
2. Gruber, William H., Raymond Vernon, “The Technology Factor in a World Trade Matrix”. In: Raymond Vernon (Ed.),The Technology factor in International Trade. New York 1970, pp. 233–272.
3. —,Dileep Mehta, “The R&D Factor in International Trade and International Investment of the United States”.Journal of Political Economy, Vol. 75,1967, pp. 20–37.
4. Hirsch, Seev, “Hypotheses Regarding Trade between Developing and Industrial Countries”. In: Herbert Giersch (Ed.),The International Division of Labor. Tübingen 1974, pp. 65–82.
5. —,Han Bijaoui, “R&D Intensity and Export Performance: A Micro View”.Weltwirtschaftliches Archiv, Vol. 121, 1985, pp. 238–251.