APA (7th ed.) Citation

Cicerón, M. T., Griffin, M. T., & Atkins, E. M. (2000). On duties. University Press.

Chicago Style (17th ed.) Citation

Cicerón, Marco Tulio, Miriam T. Griffin, and E. M. Atkins. On Duties. Cambridge [etc.]: University Press, 2000.

MLA (9th ed.) Citation

Cicerón, Marco Tulio, et al. On Duties. University Press, 2000.