Columbia subject headings:
Agricultural laborers--England--East Riding of Yorkshire.
Draft horses--England--East Riding of Yorkshire.
Harvard subject headings:
Agricultural laborers--England--Yorkshire--History--19th century.
Agricultural laborers--England--Yorkshire--History--20th century.
Agriculture--England--Yorkshire--History--19th century.
Agriculture--England--Yorkshire--History--20th century.
Yorkshire (England)--History.
Princeton subject headings:
Agricultural laborers--England--Yorkshire--History--19th century.
Agricultural laborers--England--Yorkshire--History--20th century.
Agriculture--England--Yorkshire--History--19th century.
Agriculture--England--Yorkshire--History--20th century.
Yorkshire (England)--History.