Columbia subject headings:
Hesse, Hermann, 1877-1962--Correspondence.
Hubacher, Hermann, 1885-1976--Correspondence.
Harvard subject headings:
Artists--Switzerland--Correspondence.
Authors, German--20th century--Correspondence
Hesse, Hermann, 1877-1962. Correspondence.
Hubacher, Hermann, 1885-1976--Correspondence.
Princeton subject headings:
Hesse, Hermann, 1877-1962. Correspondence.
Hubacher, Hermann, 1885-1976--Correspondence.