nd of the 18th Century. Red Sea Press. ISBN 978-0-932415-19-6.↑ In defence of the Eritrean revolution against Ethiopian social chauvinists. AESNA. 1978. p. 38. Later in their history, the Denkel lowlands of Eritrea were part of the Sultanate of Aussa, which came into being towards the end of the sixteenth century.↑ Abir, Mordechai (1968) The era of the princes: the challenge of Islam and the re-unification of the Christian empire, 1769–1855. London: Longmans, p. 23 n. 1.↑ Ullendorff, Edward. The Ethiopians: An Introduction to Country and People 2nd ed., p. 90. Oxford University Press (London), 1965. ISBN 0-19-285061-X.↑ Chisholm, Hugh, ed (1911). "Eritrea". එන්සයික්ලොපීඩියා බ්‍රිටැනිකා. 9 (11th ed.). Cambridge University Press. p. 747. ↑ Chisholm, Hugh, ed (1911). "Abyssinia". එන්සයික්ලොපීඩියා බ්‍රිටැනිකා. 1 (11th ed.). Cambridge University Press. p. 94. ↑ Olivieri, Emilio (1888) La Ferrovia Massaua-Saati සංරක්ෂණය කළ පිටපත 12 ඔක්තෝබර් 2013 at the Wayback Machine (report on 