SAMUEL, Jacob, Jaurnal of a missionary tour through the Desert of Arabia to Bagdad, Edinburg ١٨٤٤
SCHUTZ, Paul, Zwischen Nil und Kaukasus, Kassel ١٩٥٣
STORM, W. Harold, Whiter Arabia ? London, New York ١٩٣٨
TRIMINGHAM, John Spencer, The Christian Approach to Islam in the Sudan, London ١٩٤٨
Islam in Ethiopia, London ١٩٤٨ - - --
TUCHMAN, Barbara W, Bible and Sword, New York ١٩٥٦
WILSON, J. Christy, The Christian Message to Islam, New York ١٩٥٠