Columbia subject headings:
Ackerknecht, Erwin, 1880-1960--Archives--Catalogs.
Critics--Germany--Archives--Catalogs.
Librarians--Germany--Archives--Catalogs.
Harvard subject headings:
Ackerknecht, Erwin, 1880-1960--Archives--Catalogs.
Deutsches Literaturarchiv (Germany)--Catalogs.
Princeton subject headings:
Ackerknecht, Erwin, 1880-1960--Archives--Catalogs.
Critics--Germany--Archives--Catalogs.
Librarians--Germany--Archives--Catalogs.