- Parlamento italiano: www.camera.it; www.senato.it
- IDEA: http://www.idea.int/
- Inter Parliamentary Union: http://www.ipu.org/english/home.htm
- World Values Survey: http://www.worldvaluessurvey.org/wvs.jsp
- Comparative Parliamentary Democracy Project: http://www.pol.umu.se/ccpd/CCPD/index.asp
- Polity IV: http://www.systemicpeace.org/polity/polity4.htm
- Freedom House: https://freedomhouse.org/
- Indice degli Stati Falliti del Found for Peace: http://www.foundforpeace.org/
- Per informazioni e dati sugli stati falliti: http://globalpolicy.gmu.edu/
