1. Alesina, A., Angeloni, I., & Schuknecht, L. (2001). What does the European Union do?”. NBER Working paper, 8647.
2. Baldwin, R., and Wyplosz C. “The Economics of European Integration”, McGraw Hill, 2012, pp. 90–100, 560
3. Buchanan, J. (1954). Social choice, democracy and free markets”. Journal of Political Economy, 62, 114–123.
4. Constitution of the Italian Republic. http://www.quirinale.it/qrnw/static/constituizone/pdf/constituizone_inglese_01.pdf
5. Dorigo, S.M.,(Ed.), Interventi e Relazioni parlamentari, Vol. II, Dalla Consulta nazionale al Senato della Repubblica (1945–1958), Fondazione Luigi Einaudi, Torino, 1982.