Columbia subject headings:
Schopenhauer, Arthur, 1788-1860--Criticism and interpretation.
Solipsism.
Wittgenstein, Ludwig, 1889-1951--Criticism and interpretation.
Harvard subject headings:
Schopenhauer, Arthur, 1788-1860--Criticism and interpretation.
Solipsism.
Wittgenstein, Ludwig, 1889-1951--Criticism and interpretation.
Princeton subject headings:
Schopenhauer, Arthur, 1788-1860.
Solipsism.
Wittgenstein, Ludwig, 1889-1951.