@inbook{NBERc5099,
 Crossref = "NBERdaly72-1",
 title = "The Elasticity of Substitution as a Variable in World Trade",
 author = "Irving B. Kravis and Robert E. Lipsey",
 BookTitle = "International Comparisons of Prices and Output",
 Publisher = "NBER",
 pages = "369-398",
 year = "1972",
 URL = "http://www.nber.org/chapters/c5099",
}
@book{NBERdaly72-1,
 title = "International Comparisons of Prices and Output",
 author = "D. J. Daly",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1972",
 URL = "http://www.nber.org/books/daly72-1",
}