@inbook{NBERc11616,
 Crossref = "NBERfree09-1",
 title = "Introduction to "Science and Engineering Careers in the United States: An Analysis of Markets and Employment"",
 author = "Richard B. Freeman and Daniel L. Goroff",
 BookTitle = "Science and Engineering Careers in the United States: An Analysis of Markets and Employment",
 Publisher = "University of Chicago Press",
 pages = "1-16",
 year = "2009",
 month = "June",
 URL = "http://www.nber.org/chapters/c11616",
}
@book{NBERfree09-1,
 title = "Science and Engineering Careers in the United States: An Analysis of Markets and Employment",
 author = "Richard B. Freeman and Daniel Goroff",
 institution = "National Bureau of Economic Research",
 type = "Book",
 publisher = "University of Chicago Press",
 year = "2009",
 URL = "http://www.nber.org/books/free09-1",
}