Columbia subject headings:
Slave trade--Africa, Eastern--History--19th century.
Slave trade--Arabian Peninsula--History--19th century.
Slave trade--Indian Ocean Region--History--19th century.
Harvard subject headings:
Slave trade--Africa, Eastern--History--19th century.
Slave trade--Arabian Peninsula--History--19th century.
Slave trade--Indian Ocean Region--History--19th century.
Princeton subject headings:
Slave trade--Africa, Eastern--History--19th century.
Slave trade--Arabian Peninsula--History--19th century.
Slave trade--Indian Ocean Region--History--19th century.