Benn and R. S. Petters The Principles of Political Thought: Social Foundations of the Democratic State. New York: The Free Press, 1965. Chapter 10.
Berger Fred R., ed. Freedom of Expression. Belmont, CA: Wadsworth, 1980. Classic articles on censorship.
Berlin Isaiah. Four Essays on Liberty. New York: Oxford University Press, 1969. See particularly the essay "Two Concepts of Liberty."
Feinberg Joel. Harm to Others: The Moral Limits of the Criminal Law. New York: Oxford University Press, 1984.
-----. Social Philosophy. Englewood Cliffs, New Jersey: Prentice-Hall, 1973.
Hart H. L. A. Law, Liberty and Morality. New York: Random House, 1966.
Mill John Stuart. On Liberty. 1859. (Widely available in a variety of editions.)
Nielsen Kai. Equality and Liberty. Totowa, N.J.: Rowman and Allenheld, 1985.
Oppenheim Felix E. Dimensions of Freedom. New York: St. Martin's, 1961.
Wasserstrom Richard, ed. Morality and the Law. Belmont, California: Wadsworth, 1971. Contains articles oy Devlin, Dworkin, Hart, and others which were discussed in this chapter.
Wolff Robert Paul. The Poverty of Liberalism. Boston: Beacon Press, 1968. Chapter One, "Liberty."
Daniels Norman. "Equal Liberty and the Unequal Worth of Liberty" in Norman Daniels, ed., Reading Rawls: Critical Studies of A Theory of Justice. New York: Basic Books, 1975, pp. 253-81.
MacCallum Gerald C., Jr. "Negative and Positive Freedom." The Philosophical Review, Vol. LXXVI, No. 3 ( 1967), pp. 312-34.
Marcuse Herbert. "Repressive Tolerance," in Robert Paul Wolff, Barrington Moore Jr., and Herbert Marcuse, A Critique of Pure Tolerance. Boston: Beacon Press, 1969.
Parent William A. "Some Recent Work on the Concept of Liberty." American Philosophical Quarterly, Vol 11, No. 3 ( 1974), pp. 149-66.
Wertheimer Alan. "Social Theory and the Assessment of Social Freedom." Polity, Vol 7, No. 3 ( 1974), pp. 334-60.