Columbia subject headings:
Harvard subject headings:
Hofmann, Walter, 1879-1952.
Librarians--Germany--History--20th century.
Librarians--United States--History--20th century.
Library science--History--20th century.
Reading interests--Research--Germany--History--20th century.
Reading interests--Research--United States--History--20th century.
Waples, Douglas, 1893-1978.
Princeton subject headings:
Hofmann, Walter, 1879-1952.
Library science--Germany--History--20th century.
Library science--United States--History--20th century.
Readership surveys--Germany--History--20th century.
Readership surveys--United States--History--20th century.
Reading interests--Research--Germany--History--20th century.
Reading interests--Research--United States--History--20th century.
Waples, Douglas, 1893-1978.