1. Alke, Matthias. 2015. Verstetigung von Kooperation. In Eine Studie zu Weiterbildungsorganisationen in vernetzten Strukturen. Wiesbaden: Springer.
2. Armingeon, Klaus. 2006. Political participation and associational involvement. In Citizenship and Involvement in European Democracies. A Comparative Analysis, ed. Jan W. Van Deth, José Ramón Montero, and Anders Westholm. London: Routledge.
3. Badescu, Gabriel, and Katja Neller. 2006. Explaining associational involvement. In Citizenship and Involvement in European Democracies. A Comparative Analysis, ed. Jan W. Van Deth, José Ramón Montero, and Anders Westholm. London: Routledge.
4. Barber, Benjamin R. 2003. Strong Democracy: Participatory Politics for a New Age. Berkeley: University of California Press.
5. Bobbio, Norberto, and Richard Bellamy. 1987. The Future of Democracy: A Defence of the Rules of the Game. Minneapolis: University of Minnesota Press.