Columbia subject headings:
Harvard subject headings:
Authors, Austrian--20th century--Correspondence
Ficker, Ludwig von, 1880-1967. Correspondence.
Philosophers--Correspondence.
Wittgenstein, Ludwig, 1889-1951--Correspondence.
Princeton subject headings:
Authors, Austrian--20th century--Correspondence.
Ficker, Ludwig von, 1880-1967. Correspondence.
Philosophers--Correspondence.
Wittgenstein, Ludwig, 1889-1951--Correspondence.