Church and State in Ethiopia: 1270 - 1527 by Tadesse Tamrat
https://ia802908.us.archive.org/4/items/church-and-state-in-ethiopia/Church%20and%20state%20in%20ethiopia.pdf
A digital archive on Eritrea and Ethiopia in particular and on the Horn of Africa, in general
A digital archive on Eritrea and Ethiopia in particular and on the Horn of Africa, in general