Columbia subject headings:
Natural history--Philosophy--Congresses.
Wittgenstein, Ludwig, 1889-1951--Congresses.
Harvard subject headings:
Natural history--Philosophy--Congresses.
Science--Philosophy--Congresses
Wittgenstein, Ludwig, 1889-1951--Congresses.
Princeton subject headings:
Natural history--Philosophy--Congresses.
Wittgenstein, Ludwig, 1889-1951--Congresses.