1. Berlin, Isaiah. 1969. Four Essays on Liberty. Oxford: Oxford University Press.
2. Binmore, Ken. 2005. Natural Justice. Oxford/New York: Oxford University Press.
3. Constant, Benjamin. 1819. The Liberty of Ancients Compared with That of Moderns. Online Library of Liberty, Liberty Fund. http://oll.libertyfund.org/titles/2251 . Retrieved 4 Sept 2015.
4. de Jasay, Anthony. 2010. Ordered Anarchy and Contractarianism. Philosophy 85: 399–403.
5. Ferguson, Adam. 1995 [1767]. An Essay on Civil Society, ed. Fania Oz-Salzberger. Cambridge: Cambridge University Press.