APA (7th ed.) Citation

Mill, J. S., & Gray, J. (1991). On liberty and other essays. Oxford University Press.

Chicago Style (17th ed.) Citation

Mill, John Stuart, and John Gray. On Liberty and Other Essays. Oxford, New York: Oxford University Press, 1991.

MLA (9th ed.) Citation

Mill, John Stuart, and John Gray. On Liberty and Other Essays. Oxford University Press, 1991.