Columbia subject headings:
Russell, Bertrand, 1872-1970.
Wittgenstein, Ludwig, 1889-1951.
Harvard subject headings:
Russell, Bertrand, 1872-1970
Wittgenstein, Ludwig, 1889-1951
Princeton subject headings:
Russell, Bertrand, 1872-1970.
Wittgenstein, Ludwig, 1889-1951.