Columbia subject headings:
Authors, German--20th century--Correspondence.
Thoma, Ludwig, 1867-1921--Correspondence.
Harvard subject headings:
Authors, German--20th century--Correspondence
Thoma, Ludwig, 1867-1921--Correspondence.
Princeton subject headings:
Authors, German--20th century--Correspondence.
Thoma, Ludwig, 1867-1921--Correspondence.