Order:
  1.  5
    Plato's Protagoras: a Socratic commentary.B. A. F. Hubbard - 1982 - Chicago: University of Chicago Press. Edited by E. S. Karnofsky & Plato.
  2.  9
    Plato's Protagoras.B. A. F. Hubbard & E. S. Karnofsky - 1986 - Noûs 20 (2):269-271.
  3. Commentary.B. A. F. Hubbard, E. S. Plato & Karnofsky - 1982