APA (7th ed.) Citation

Gray, J., Mill, J. S., & Smith, G. W. (1991). J.S. Mill, On liberty in focus. Routledge.

Chicago Style (17th ed.) Citation

Gray, John, John Stuart Mill, and G. W. Smith. J.S. Mill, On Liberty in Focus. London: Routledge, 1991.

MLA (9th ed.) Citation

Gray, John, et al. J.S. Mill, On Liberty in Focus. Routledge, 1991.