Columbia subject headings:
Kraus, Karl, 1874-1936--Correspondence.
Wolff, Kurt, 1887-1963--Correspondence.
Harvard subject headings:
Authors, Austrian--20th century--Correspondence
Kraus, Karl, 1874-1936--Correspondence.
Publishers and publishing--Germany--Correspondence
Wolff, Kurt, 1887-1963--Correspondence.
Princeton subject headings:
Kraus, Karl, 1874-1936--Correspondence.
Wolff, Kurt, 1887-1963--Correspondence.