1. Baldwin, R. E., & Cain, G. G. (1997). Shifts in U.S. relative wages: the role of trade, technology and factor endowments. NBER Working Paper No. 5934.
2. Bartelsman, E. J., & Gray, W. (1996). NBER manufacturing productivity database. NBER Technical Working Paper No. 205.
3. Separability of capital and labor in US manufacturing;Clark;Economics Letters,1998
4. Economic integration and the American worker: an overview;Collins,1998
5. Dasgupta, I., & Osang, T. (2000). Globalization and relative wages: further evidence from U.S. manufacturing industries. Southern Methodist University Working Paper No. 2002.