Columbia subject headings:
Harvard subject headings:
Documentary photography--Germany--Congresses.
Museums and photography--Germany--Congresses.
Photography, Industrial--Germany--Congresses.
Working class--Germany--Pictorial works--Congresses.
Princeton subject headings:
Labor journalism--Germany--History--20th century--Congresses.
Labor movement--Germany--History--20th century--Congresses.
Museums and photography--Congresses.
Photojournalism--Germany--History--20th century--Congresses.