@inbook{NBERc6185,
 Crossref = "NBERfeen97-1",
 title = "Market-Access Effects of Trade Liberalization: Evidence from the Canada-U.S. Free Trade Agreement",
 author = "Keith Head and John Ries",
 BookTitle = "The Effects of U.S. Trade Protection and Promotion Policies",
 Publisher = "University of Chicago Press",
 pages = "323-342",
 year = "1997",
 month = "January",
 URL = "http://www.nber.org/chapters/c6185",
}
@book{NBERfeen97-1,
 title = "The Effects of U.S. Trade Protection and Promotion Policies",
 author = "Robert C. Feenstra",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1997",
 URL = "http://www.nber.org/books/feen97-1",
}