"...där kryddor och ädla metaller var lika vanliga som salt i Portugal". Stephanie E. Smallwood, 2009, Saltwater Slavery: A Middle Passage from Africa to American Diaspora, sid. 11. ISBN 9780674043770.
Hugh Thomas, 1997, The Slave Trade: The Story of the Atlantic Slave Trade: 1440 - 1870, sid. 54. ISBN 9780684835655.
Anouar Boukhars, Jacques Roussellier, 2013, Perspectives on Western Sahara: Myths, Nationalisms, and Geopolitics, sid. 6-7. ISBN 9781442226869.