@inbook{NBERc3528,
 Crossref = "NBERfuch73-1",
 title = "Differences Over Time, 1948-68: A Statistical Decomposition",
 author = "Victor R. Fuchs and Marcia J. Kramer",
 BookTitle = "Determinants of Expenditures for Physicians' Services in the United States",
 Publisher = "UMI",
 pages = "5-20",
 year = "1973",
 URL = "http://www.nber.org/chapters/c3528",
}
@book{NBERfuch73-1,
 title = "Determinants of Expenditures for Physicians' Services in the United States",
 author = "Victor R. Fuchs and Marcia J. Kramer",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "UMI",
 year = "1973",
 URL = "http://www.nber.org/books/fuch73-1",
}