Google Scholar limits your results to academic resources.
tip: To get the link when using Google Scholar off campus, go to Scholar Settings and choose Duke from Library Links.
You can also set your preferred citation tool (Endnote, Refworks) in Scholar Settings for one-click citation export.
Think Tank Search
From Harvard's Kennedy School of Government library; custom Google search + list of hundreds of US and international think tanks
Think tanks are defined by the above as institutions affiliated with universities, governments, advocacy groups, foundations, non-governmental organizations, and businesses that generate public policy research, analysis, and activity.
Tips: Search these selected think tanks by keywords to find research and analysis.
If one seems most relevant to your topic, go to the home page and mine the site for publications, issues, research, and links to other organizations.
Global Go To Think Tank Index (U Pennsylvania)
American Policy Directory (U Oregon)
Think Tank List (WorldPress.org)
Human Rights Web Archive
From Columbia U., preserves web publications and sites on human rights, at risk of disappearing
Labor and the Left
From NYU, archived web sites arranged in topical collections