1. Hunwick , ‘Songhay, Bornu, and Hausaland’, 205–6
2. ‘Bariba States’, 84.
3. Lovejoy , ‘Hausa Kola Trade’, 207–10.
4. Lavers , ‘Kanem and Borno’.
5. Kanem, Bornu, and the Fazzān: Notes on the Political History of a Trade Route;Martin;J. Afr. Hist.,1969