@inbook{NBERc3045,
 Crossref = "NBERhell07-1",
 title = "Patents, Thickets and the Financing of Eastly-Stage Firms; Evidence from the Software Industry",
 author = "Iain M. Cockburn and Megan J. MacGarvie",
 BookTitle = "Entrepreneurship: Strategy and Structure",
 Publisher = "Journal of Economics and Management Strategy 18(3), Fall 2009 (Blackwell Publishing)",
 year = "2007",
 month = "September",
 URL = "http://www.nber.org/chapters/c3045",
}
@book{NBERhell07-1,
 title = "Entrepreneurship: Strategy and Structure",
 author = "Thomas Hellman and Scott Stern",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "Journal of Economics and Management Strategy 18(3), Fall 2009 (Blackwell Publishing)",
 year = "2009",
 URL = "http://www.nber.org/books/hell07-1",
}