1. http://www.whitehouse.gov/sites/default/files/doubling%2011%20final.pdf
2. http://news.sciencemag.org/scienceinsider/budget_2012
3. Intersociety Working Group AAAS Report XXXV: Research and Development FY 2011 (American Association for the Advancement of Science, 2010); available at
http://www.aaas.org/spp/rd/rdreport2011
.
4. Organisation for Economic Co-operation and Development OECD Factbook 2008: Economic, Environmental and Social Statistics (OECD Publishing, 2008); available at
http://www.sourceoecd.org/factbook
.