Columbia subject headings:
Harvard subject headings:
Authors, German--19th century--Biography
Authors, German--20th century--Biography
Berlin (Germany)--Intellectual life--19th century.
Berlin (Germany)--Intellectual life--20th century
Berlin (Germany)--Social life and customs--19th century.
Berlin (Germany)--Social life and customs--20th century.
Essayists--Germany--Biography.
Hardekopf, Ferdinand
Theater--Germany--Berlin--History--19th century.
Theater--Germany--Berlin--History--20th century.
Princeton subject headings:
Hardekopf, Ferdinand--Correspondence.
Personal correspondence.