Columbia subject headings:
Artists--Germany--Correspondence.
Authors, German--Correspondence.
Hauptmann, Gerhart, 1862-1946--Correspondence.
Hauptmann, Ivo, 1886-1973--Correspondence.
Harvard subject headings:
Hauptmann, Gerhart, 1862-1946--Correspondence.
Hauptmann, Ivo, 1886-1973--Correspondence.
Princeton subject headings:
Artists--Germany--Correspondence.
Authors, German--Correspondence.
Hauptmann, Gerhart, 1862-1946--Correspondence.
Hauptmann, Ivo, 1886-1973--Correspondence.
Personal correspondence.