@inbook{NBERc9094,
 Crossref = "NBERsmit77-1",
 title = "Family Labor Supply over the Life Cycle",
 author = "James P. Smith",
 BookTitle = "Explorations in Economic Research, Volume 4, number 2",
 Publisher = "NBER",
 pages = "1-72",
 year = "1977",
 month = "June",
 URL = "http://www.nber.org/chapters/c9094",
}
@book{NBERsmit77-1,
 title = "Explorations in Economic Research, Volume 4, number 2",
 author = "NBER",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1977",
 URL = "http://www.nber.org/books/smit77-1",
}