Columbia subject headings:
Slave trade--Sulu (Sultanate)
Sulu (Sultanate)--Commerce.
Sulu (Sultanate)--History.
Harvard subject headings:
Ethnology--Philippines--Sulu Archipelago.
Slave trade--Philippines--Sulu Archipelago--History.
Sulu Archipelago (Philippines)--Commerce--History.
Sulu Archipelago (Philippines)--History.
Princeton subject headings: