Columbia subject headings:
Constructivism (Philosophy)--Congresses.
Realism--Congresses.
Relativity--Congresses.
Wittgenstein, Ludwig, 1889-1951--Congresses.
Harvard subject headings:
Constructivism (Philosophy)--Congresses.
Realism--Congresses.
Relativity--Congresses.
Wittgenstein, Ludwig, 1889-1951--Congresses.
Princeton subject headings: