Columbia subject headings:
Harvard subject headings:
Arabian Peninsula--Economic conditions--History--19th century.
Arabian Peninsula--Population--History--19th century.
Labor supply--Arabian Peninsula--History--19th century.
Labor--Arabian Peninsula--History--19th century.
Princeton subject headings:
Arabian Peninsula--Economic conditions--History--19th century.
Arabian Peninsula--Population--History--19th century.
Labor--Arabian Peninsula--History--19th century.