Columbia subject headings:
Harvard subject headings:
Capitalism--Germany--History--21st century.
Capitalism--History--21st century.
Exploitation--History--21st century.
Marxian school of sociology--Germany--History--21st century.
Social classes--History--21st century.
Working class--Germany--History--21st century.
Working class--History--21st century.
Working class--Philosophy.
Princeton subject headings:
Working class--Germany.