@inbook{NBERc11515,
 Crossref = "NBERmarg00-1",
 title = "Antebellum Wages and Labor Markets: A New Interpretation",
 author = "Robert A. Margo",
 BookTitle = "Wages and Labor Markets in the United States, 1820-1860",
 Publisher = "University of Chicago Press",
 pages = "142-157",
 year = "2000",
 month = "January",
 URL = "http://www.nber.org/chapters/c11515",
}
@book{NBERmarg00-1,
 title = "Wages and Labor Markets in the United States, 1820-1860",
 author = "Robert A. Margo",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2000",
 URL = "http://www.nber.org/books/marg00-1",
}