@inbook{NBERc7381,
 Crossref = "NBERtrip83-1",
 title = "Intermetropolitan Wage Differentials in the United States",
 author = "George Johnson",
 BookTitle = "The Measurement of Labor Cost",
 Publisher = "University of Chicago Press",
 pages = "309-332",
 year = "1983",
 URL = "http://www.nber.org/chapters/c7381",
}
@book{NBERtrip83-1,
 title = "The Measurement of Labor Cost",
 author = "Jack E. Triplett",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1983",
 URL = "http://www.nber.org/books/trip83-1",
}