1. Aligica, P., & Chamlee-Wright, E. 2015. Polycentricity and the principles of effective co-governance. In E. Chamlee-Wright (Ed.), Liberal learning and the art of self-governance. New York: Routledge.
2. Buchanan, J. 2000. Freedom in the constitutional contract. College Station, TX:Texas A&M Press.
3. Bromwich, D. 2016. What we are allowed to say. London Review of Books, 38(18), 3–10.
4. Chemerinski, E., & Gillman, H. 2017. Free speech on campus. New Haven:Yale University Press.
5. Cohen, A.J. 2014. Toleration. Cambridge: Polity Press.