Schiappa, E. (2003). Protagoras and logos: A study in Greek philosophy and rhetoric (2nd ed.). University of South Carolina Press.
Lua i Stíl Chicago (17ú heag.)Schiappa, Edward. Protagoras and Logos: A Study in Greek Philosophy and Rhetoric. 2nd ed. Columbia, S.C.: University of South Carolina Press, 2003.
Lua MLA (9ú heag.)Schiappa, Edward. Protagoras and Logos: A Study in Greek Philosophy and Rhetoric. 2nd ed. University of South Carolina Press, 2003.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.