Columbia subject headings:
Grocery trade--Germany (West)--History--20th century.
Retail trade--Germany (West)--History--20th century.
Self-service stores--Germany (West)--History--20th century.
Harvard subject headings:
Grocery trade--Germany (West)--History--20th century.
Retail trade--Germany (West)--History--20th century.
Self-service stores--Germany (West)--History--20th century.
Princeton subject headings: