Driver, J. (2006). Ethics: the fundamentals (Vol. 1). Blackwell Publishing. https://ebookcentral.proquest.com/lib/gla/detail.action?docID=1204064
Grube, G. M. A. & Plato. (1992). The Republic (C. D. C. Reeve, Ed.). Hackett Publishing Company. https://ebookcentral.proquest.com/lib/gla/detail.action?docID=735561
Rowe, C. J., Broadie, S., & Aristotle. (2002). Nicomachean ethics. Oxford University Press.
Taylor, C. C. W. & Plato. (2002). Protagoras. Oxford University Press.