Columbia subject headings:
Buber, Martin, 1878-1965.
Ethics, Modern--20th century.
Religion--History--20th century.
Simmel, Georg, 1858-1918.
Harvard subject headings:
Buber, Martin, 1878-1965
Ethics, Modern--20th century.
Religion--History--20th century
Simmel, Georg, 1858-1918
Princeton subject headings:
Buber, Martin, 1878-1965.
Ethics, Modern--20th century.
Religion--History--20th century.
Simmel, Georg, 1858-1918.