@inbook{NBERc1731,
 Crossref = "NBERmill33-2",
 title = "Changes in Physical Production, Industrial Productivity and Manufacturing Costs, 1927-1932",
 author = "Frederick C. Mills",
 BookTitle = "Changes in Physical Production, Industrial Productivity and Manufacturing Costs, 1927-1932",
 Publisher = "NBER",
 pages = "1-8",
 year = "1933",
 URL = "http://www.nber.org/chapters/c1731",
}
@book{NBERmill33-2,
 title = "Changes in Physical Production, Industrial Productivity and Manufacturing Costs, 1927-1932",
 author = "Frederick C. Mills",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1933",
 URL = "http://www.nber.org/books/mill33-2",
}