Columbia subject headings:
Harvard subject headings:
Metaphysics--History--20th century
Phenomenologists--History--20th century.
Phenomenology--History--20th century
Philosophers--History--20th century.
Princeton subject headings:
Metaphysics--History--20th century.
Phenomenologists--History--20th century.
Phenomenology--History--20th century.
Philosophers--History--20th century.