Columbia subject headings:
Engelhardt, H. Tristram (Hugo Tristram), Jr., 1941-2018.
Ethics, Modern--20th century.
Gewirth, Alan.
Harvard subject headings:
Engelhardt, H. Tristram (Hugo Tristram), Jr., 1941-2018--Ethics.
Ethics, Modern--20th century.
Gewirth, Alan--Ethics.
Princeton subject headings:
Engelhardt, H. Tristram (Hugo Tristram), Jr., 1941-
Ethics, Modern--20th century.
Gewirth, Alan.