Columbia subject headings:
Klabund, 1890-1928--Correspondence.
Harvard subject headings:
Authors, German--20th century--Biography
Authors, German--20th century--Correspondence
Bruno, Irene, 1878-1949--Correspondence.
Heberle, Irene, -1918--Correspondence.
Heberle, Max, 1864-1927--Correspondence.
Klabund, 1890-1928--Correspondence.
Princeton subject headings:
Klabund, 1890-1928--Correspondence.