@inbook{NBERc4310,
 Crossref = "NBERingr77-1",
 title = "Census Data and Housing Analysis: Old Data Sources and New Applications",
 author = "William C. Apgar, Jr.",
 BookTitle = "Residential Location and Urban Housing Markets",
 Publisher = "NBER",
 pages = "139-180",
 year = "1977",
 URL = "http://www.nber.org/chapters/c4310",
}
@book{NBERingr77-1,
 title = "Residential Location and Urban Housing Markets",
 author = "Gregory K. Ingram",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1977",
 URL = "http://www.nber.org/books/ingr77-1",
}