Columbia subject headings:
Labor disputes--England--History--20th century.
Labor disputes--Wales--History--20th century.
Police--England--History--20th century.
Police--Wales--History--20th century.
Harvard subject headings:
Labor disputes--England--History--20th century.
Labor disputes--Wales--History--20th century.
Police--England--History--20th century.
Police--Wales--History--20th century.
Princeton subject headings:
Labor disputes--England--History--20th century.
Labor disputes--Wales--History--20th century.
Police--England--History--20th century.
Police--Wales--History--20th century.