AbirMordechai. The Era of the Princes. New York: Frederick A. Praeger, 1968.
2.
AbirMordechai. “The Consolidation of the Monarchies of Enarea and Jimma in the Nineteenth Century.”Journal of African History;V, 2 (1965).
3.
BaxterP. T. W.“Acceptance and Rejection of Islam Among the Boran of the Northern Frontier District of Kenya.”LewisI. M., ed. Islam in Tropical Africa. London: Oxford University Press, 1966.
4.
BrookeClarke H.Jr.“A Study of Galla Settlements, Hararge Province, Ethiopia.” Unpublished Ph.D. dissertation. University of Nebraska, 1957.
5.
CaulkRichard. “Harar in the Nineteenth Century and the Loss of Its Independence.” Unpublished paper presented to the Interdisciplianry Seminar of the Faculties of Arts and Education: Haile Selassi I University, Addis Ababa, 1968.
6.
GreenfieldRichard. Ethiopia: A New Political History. New York/Washington/London: Frederick A. Praeger, 1965.
7.
KnutssonKarl Eric. Authority and Change. Göteborg: Elanders Boktryckeri Aktiebolag, 1967.
8.
LevineDonald N.Wax and Gold. Chicago: University of Chicago Press, 1965.
9.
LewisHerbert S.Jimma Abba Jifar: A Galla Monarchy. Madison: University of Wisconsin Press1965.
10.
LewisHerbert S.“The Origins of the Galla and Somali.”Journal of African History;VII, 1 (1966).
11.
LewisI. M.The Modern History of Somaliland. New York: Frederick A. Praeger, 1965.
12.
LewisI. M.A Pastoral Democracy. London: Oxford University Press, 1961. 1961.
13.
TippetAlan R.Peoples of Southwest Ethiopia. South Pasadena, Calif.: William Carey Library, 1970.
14.
TouvalSaadia. Somali Nationalism. Cambridge: Harvard University Press, 1963.
15.
TriminghamJ. Spencer. Islam in Ethiopia. London: Frank Cass & Co. Ltd., 1965.
