Columbia subject headings:
Ethics in literature.
Ethics--Greece--History.
Sophocles--Ethics.
Harvard subject headings:
Didactic drama, Greek--History and criticism.
Ethics in literature.
Ethics, Ancient, in literature.
Ethics, Ancient.
Ethics--Greece--History.
Mythology, Greek, in literature.
Sophocles--Ethics.
Princeton subject headings:
Ethics in literature.
Ethics--Greece--History.
Sophocles--Ethics.