Columbia subject headings:
Becker, Oskar, 1889-1964--Congresses.
Mathematics--Philosophy--Congresses.
Phenomenology--Congresses.
Harvard subject headings:
Becker, Oskar, 1889-1964--Congresses.
Mathematics--Philosophy--Congresses
Phenomenology--Congresses.
Princeton subject headings:
Becker, Oskar, 1889-1964--Congresses.
Philosophers--Germany--20th century--Congresses.
Philosophy, German--20th century--Congresses.