Columbia subject headings:
Harvard subject headings:
Slave trade--Africa--History
Slave trade--America--History
Slave trade--Europe--History.
Slavery--Africa--History
Slavery--America--History
Slavery--Economic aspects--Africa--History.
Slavery--Economic aspects--America--History.
Slavery--Economic aspects--Europe--History.
Slavery--Europe--History.
Slavery--History
Princeton subject headings:
Slave trade--Africa--History.
Slave trade--America--History.
Slave trade--Europe--History.
Slavery--America--History.
Slavery--History.