Roberto Biorcio (2002). "Italy". In Ferdinand Muller-Rommel; Thomas Poguntke (eds.). Green Parties in National Governments. Routledge. p. 42. ISBN978-1-135-28826-6.
Fabio Padovano; Roberto Ricciuti, eds. (2007). "Appendix 2". Italian Institutional Reforms: A Public Choice Perspective. Springer Science & Business Media. p. 34. ISBN978-0-387-72141-5.
Nikiforos Diamandouros; Richard Gunther, eds. (2001). "Notes to Pages 346–380". Parties, Politics, and Democracy in the New Southern Europe. JHU Press. p. 424. ISBN978-0-8018-6518-3.