APA (7th ed.) Citation

Cicero, M. T. 1., Griffin, M. T., & Atkins, E. M. (1991). On duties. Cambridge University Press.

Chicago Style (17th ed.) Citation

Cicero, Marcus Tullius 106-43, Miriam T. Griffin, and E. Margaret Atkins. On Duties. Cambridge: Cambridge University Press, 1991.

MLA (8th ed.) Citation

Cicero, Marcus Tullius 106-43, et al. On Duties. Cambridge University Press, 1991.