https://www.idea.int/data-tools/data/voter-turnout

Comprehensive source of information on voter turnout around the world.

www.psr.keele.ac.uk/parties.htm

Compendium to websites of political parties, social movements, and interest groups around the world.

www.opendemocracy.net/democracy-open_politics/article_2312.jsp

Paul Hilder, ‘Open Parties? A Map of 21st Century Democracy’, discusses alternative possible future organizational forms.

http://repositories.cdlib.org/csd/05-06

Peter Mair, ‘Democracy Beyond Parties’, Center for the Study of Democracy, University of California, Irvine, 2005. Discusses the changing politics of the party.

www.opensecrets.org

Contains a wealth of information on US party funding.