@techreport{NBERw12318,
 title = "Contributions of Zvi Griliches",
 author = "James Heckman",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "12318",
 year = "2006",
 month = "June",
 URL = "http://www.nber.org/papers/w12318",
}