Columbia subject headings:
Harvard subject headings:
Industries--Social aspects--Germany--History--20th century--Congresses.
National socialism and labor--Congresses.
Nationalsozialistische Gemeinschaft "Kraft durch Freude"--History--Congresses.
Working class--Germany--History--20th century--Congresses.
Working class--Recreation--Germany--History--20th century--Congresses.
Princeton subject headings:
Industries--Social aspects--Germany--History--20th century--Congresses.
National socialism and labor--Congresses.
Nationalsozialistische Gemeinschaft "Kraft durch Freude"--History--Congresses.
Working class--Germany--History--20th century--Congresses.
Working class--Recreation--Germany--History--20th century--Congresses.