@inbook{NBERc6304,
 Crossref = "NBERlong44-1",
 title = "The American Labor Force in World War I",
 author = "Clarence D. Long",
 BookTitle = "The Labor Force in Wartime America",
 Publisher = "NBER",
 pages = "39-49",
 year = "1944",
 URL = "http://www.nber.org/chapters/c6304",
}
@book{NBERlong44-1,
 title = "The Labor Force in Wartime America",
 author = "Clarence D. Long",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1944",
 URL = "http://www.nber.org/books/long44-1",
}