@techreport{ w9909,
 title = "How Do Patent Laws Influence Innovation? Evidence from Nineteenth-Century World Fairs",
 author = "Petra Moser",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "9909",
 year = "2003",
 month = "August",
 URL = "http://www.nber.org/papers/w9909",
}