@inbook{NBERc8349,
 Crossref = "NBERgril98-1",
 title = "The Search for R&D Spillovers",
 author = "Zvi Griliches",
 BookTitle = "R&D and Productivity: The Econometric Evidence",
 Publisher = "University of Chicago Press",
 pages = "251-268",
 year = "1998",
 month = "January",
 URL = "http://www.nber.org/chapters/c8349",
}
@book{NBERgril98-1,
 title = "R&D and Productivity: The Econometric Evidence",
 author = "Zvi Griliches",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "1998",
 URL = "http://www.nber.org/books/gril98-1",
}