1. Coughlin, C., & Wall, H. (2000). NAFTA and the Changing Pattern of State Exports. Working Paper, Federal Reserve Bank of St. Louis.
2. Cyrus, T. (2000). Why do national borders matter? Industry-level evidence. Paper presented to 2000 Canadian Economics Association Meetings in Vancouver.
3. Regional trading blocs in the world trading system;Frankel,1997
4. Why is interprovincial trade down and international trade up;Grady;Canadian Business Economics,1998
5. How much do national borders matter?;Helliwell,1998