Columbia subject headings:
Harvard subject headings:
Art and photography--Germany.
Capitalism--Germany--History--20th century--Pictorial works--Congresses.
Documentary photography--Germany--History--20th century--Congresses.
Labor movement--Germany--Social conditions--Pictorial works--Congresses.
Photography--Social aspects--Germany--History--20th century--Congresses.
Vernacular photography--Germany--History--20th century--Congresses.
Working class--Germany--Congresses.
Working class--Germany--History--20th century--Pictorial works--Congresses.
Princeton subject headings:
Art and photography--Germany.
Capitalism--Germany--History--20th century--Pictorial works--Congresses.
Documentary photography--Germany--History--20th century--Congresses.
Labor movement--Germany--Social conditions--Pictorial works--Congresses.
Working class--Germany--History--20th century--Pictorial works--Congresses.