Columbia subject headings:
Weininger, Otto, 1880-1903.
Wittgenstein, Ludwig, 1889-1951.
Harvard subject headings:
Weininger, Otto, 1880-1903
Wittgenstein, Ludwig, 1889-1951
Princeton subject headings:
Weininger, Otto, 1880-1903.
Wittgenstein, Ludwig, 1889-1951.