@inbook{NBERc3872,
 Crossref = "NBERingr78-1",
 title = "The Production of Housing Services from Existing Dwelling Units",
 author = "Gregory K. Ingram and Yitzhak Oron",
 BookTitle = "Residential Location and Urban Housing Markets",
 Publisher = "NBER",
 pages = "273-326",
 year = "1978",
 URL = "http://www.nber.org/chapters/c3872",
}
@book{NBERingr78-1,
 title = "Residential Location and Urban Housing Markets",
 author = "Gregory K. Ingram",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1978",
 URL = "http://www.nber.org/books/ingr78-1",
}