@inbook{NBERc3431,
 Crossref = "NBERhemp71-1",
 title = "Evaluations by Rating Agencies",
 author = "George H. Hempel",
 BookTitle = "The Postwar Quality of State and Local Debt",
 Publisher = "NBER",
 pages = "101-124",
 year = "1971",
 URL = "http://www.nber.org/chapters/c3431",
}
@book{NBERhemp71-1,
 title = "The Postwar Quality of State and Local Debt",
 author = "George H. Hempel",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1971",
 URL = "http://www.nber.org/books/hemp71-1",
}