M. A. Bryan & A. N. Tucker 
The Non-Bantu Languages of North-Eastern Africa [PDF ebook] 
Handbook of African Languages Part 3

Originally published in 1956, this volume presents a survey of the non-Bantu languages in the area extending south of the Sahara from Lake Chad to the Indian Ocean, together withj those of South Africa. The arrangement is primarily linguistic, in as much as larger units which show some indisputable affinities are where possible treated contiguously. Languages in the centre of the total area are discussed first, followed by thos ein the west, north, east and finally south.