@inbook{NBERc3698,
 Crossref = "NBERjust75-1",
 title = "Measuring the Obsolescence of Knowledge",
 author = "Sherwin Rosen",
 BookTitle = "Education, Income, and Human Behavior",
 Publisher = "NBER",
 pages = "199-232",
 year = "1975",
 URL = "http://www.nber.org/chapters/c3698",
}
@book{NBERjust75-1,
 title = "Education, Income, and Human Behavior",
 author = "F. Thomas Juster",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "NBER",
 year = "1975",
 URL = "http://www.nber.org/books/just75-1",
}