501 ↑ David D. Laitin and Said S. Samatar, Somalia: Nation in Search of a State (Boulder: Westview Press, 1987). ↑ Cambridge illustrated atlas, Warfare: Renaissance to Revolution, 1492–1792, by Jeremy Black pg 9 ↑ "Local History in Ethiopia" Archived 28 February 2008 at the Wayback Machine (pdf) The Nordic Africa Institute website (accessed 28 January 2008) ↑ Mohammed Hassen, The Oromo of Ethiopia: A History (1570–1860) Trenton: Red Sea Press, 1994.