@inbook{NBERc9715,
 Crossref = "NBERunkn51-2",
 title = "Introduction to "Studies in Income and Wealth, Volume 14"",
 author = "Martin R. Gainsbrugh",
 BookTitle = "Studies in Income and Wealth, Volume 14",
 Publisher = "NBER",
 pages = "1-4",
 year = "1951",
 URL = "http://www.nber.org/chapters/c9715",
}
@book{NBERunkn51-2,
 title = "Studies in Income and Wealth, Volume 14",
 author = "Conference on Research in Income and Wealth",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1951",
 URL = "http://www.nber.org/books/unkn51-2",
}