1. ↑ Nordsieck, Wolfram. "Parties and Elections in Europe".
2. 1 2 McAnulla 2006.

บรรณานุกรม

• McAnulla, Stuart (2006). British Politics: A Critical Introduction. A&C Black. ISBN 0-826-46155-7.CS1 maint: ref=harv (link)
• Johnston, Larry (2007). Politics: An Introduction to the Modern Democratic State. University of Toronto Press. ISBN 1-4426-0040-3.CS1 maint: ref=harv (link)
• Johnston, Larry (2011). Politics: An Introduction to the Modern Democratic State. University of Toronto Press. ISBN 1-4426-0533-2.CS1 maint: ref=harv (link)