Bechtold, Peter K. (2015). «Languages»(PDF). In: Berry, LaVerle. Sudan: a country study 5th ed. Washington, D.C.: Federal Research Division, Library of Congress. pp. 77–79. ISBN978-0-8444-0750-0. Este artigo incorpora texto desta fonte, que está no domínio público. Though published in 2015, this work covers events in the whole of Sudan (including present-day South Sudan) until the 2011 secession of South Sudan.