Columbia subject headings:
Harvard subject headings:
Merchants--Scotland--Shetland--Biography.
Truck system--Scotland--Shetland.
Williamson, James, 1800-1872.
Princeton subject headings:
Mid Yell (Shetland)--History--Sources.
Shetland (Scotland)--Economic conditions--Sources.
Shetland (Scotland)--History--Sources.
Williamson, James, 1800-1872.