Ancient civilizations of Africa / Edited by I. Hrbek - Abridged Edition. Volume Three - London [England] : Berkeley, Calif. : Paris : J. Currey ; University of California Press ; UNESCO, 1990. - xx, 420 p. : ill., maps ; 21 cm. - General history of Africa / International Scientific Committee for the Drafting of a General History of Africa (UNESCO) ; 2 .