Axel (2004). "Angola: Slave Trade, Abolition of". in Shillington, Kevin. Encyclopedia of African History. 1. Routledge. pp. 131–133. ISBN 1-57958-245-1. ↑ Global Investment and Business Center (1 January 2006). Angola in the Eighteenth Century: Slave trading in the 1700s. Int'l Business Publications. p. 153. ISBN 0739716069. {{cite book}}: |author= has generic name (help); |work= ignored (help)↑ World Bank. The History of Brazil–Africa Relations (PDF). p. 27. 30 May 2016 දින පැවති මුල් පිටපත වෙතින් සංරක්ෂිත පිටපත (PDF). සම්ප්‍රවේශය 14 May 2016. {{cite book}}: |work= ignored (help)↑ Collelo, Thomas, ed. (1991). Angola, a Country Study. Area Handbook Series (Third ed.). Washington, D.C.: Department of the Army, American University. pp. 14–26. ISBN 978-0160308444.↑ Baynes, T. S., ed (1878). "Angola". Encyclopædia Britannica. 2 (9th ed.). New York: Charles Scribner's Sons. p. 45. ↑ Iliffe, John (2007) Africans: the history of a continent සංරක්ෂණය කළ පිටපත 10 ජූනි 2016 at the Wayb