@inbook{NBERc8913,
 Crossref = "NBERrose81-1",
 title = "Black Economic Progress after 1964: Who Has Gained and Why?",
 author = "Richard B. Freeman",
 BookTitle = "Studies in Labor Markets",
 Publisher = "University of Chicago Press",
 pages = "247-294",
 year = "1981",
 URL = "http://www.nber.org/chapters/c8913",
}
@book{NBERrose81-1,
 title = "Studies in Labor Markets",
 author = "Sherwin Rosen",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1981",
 URL = "http://www.nber.org/books/rose81-1",
}