@inbook{NBERc10134,
 Crossref = "NBERhult01-1",
 title = "Productivity of the U.S. Agricultural Sector: The Case of Undesirable Outputs",
 author = "V. Eldon Ball and Rolf Fare and Shawna Grosskopf and Richard Nehring",
 BookTitle = "New Developments in Productivity Analysis",
 Publisher = "University of Chicago Press",
 pages = "541-586",
 year = "2001",
 month = "January",
 URL = "http://www.nber.org/chapters/c10134",
}
@book{NBERhult01-1,
 title = "New Developments in Productivity Analysis",
 author = "Charles R. Hulten and Edwin R. Dean and Michael J. Harper",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2001",
 URL = "http://www.nber.org/books/hult01-1",
}