Washington and Lee University
The W&L University Library's list of public policy groups includes its own search engine.
W&L researchers can search for materials (documents, reports, studies, articles, etc.) within the Web sites of important groups by using the following databases:
Our subscription to Associations Unlimited enables W&L researchers to identify groups within particular subject areas from a list of over 450,000 non-profit organizations.
Very good subject-oriented listings of such groups are provided by Vanderbilt University and Washington State University.
Additional lists of "think tanks" and other non-governmental policy groups, with descriptions, are available from Project Vote Smart and CDISS (Centre for Defense and International Security Studies).
The World Press Review maintains an alphabetically-arranged international list.