@inbook{NBERc4212,
 Crossref = "NBERunkn72-3",
 title = "NBER Report Nine",
 author = "",
 BookTitle = "NBER Report Nine",
 Publisher = "NBER",
 year = "1972",
 URL = "http://www.nber.org/chapters/c4212",
}
@book{NBERunkn72-3,
 title = "NBER Report Nine",
 author = "NBER",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1972",
 URL = "http://www.nber.org/books/unkn72-3",
}