↑Robert Stock, Africa South of the Sahara, Second Edition: A Geographical Interpretation, (The Guilford Press: 2004), p. 26
↑Michael Hodd, East Africa Handbook, 7th Edition, (Passport Books: 2002), p. 21: "To the north are the countries of the Horn of Africa comprising Ethiopia, Eritrea, Djibouti and Somalia."
↑Encyclopaedia Britannica, inc, Jacob E. Safra, The New Encyclopaedia Britannica, (Encyclopaedia Britannica: 2002), p.61: "The northern mountainous area, known as the Horn of Africa, comprises Djibouti, Ethiopia, Eritrea, and Somalia."
↑Sandra Fullerton Joireman, Institutional Change in the Horn of Africa, (Universal-Publishers: 1997), p.1: "The Horn of Africa encompasses the countries of Ethiopia, Eritrea, Djibouti and Somalia. These countries share similar peoples, languages, and geographical endowments."
↑Walter RC, Buffler RT, Bruggemann JH, et al. (May 2000). "Early human occupation of the Red Sea coast of Eritrea during the last interglacial". Nature 405 (6782): 65–9. doi:10.1038/35011048. PMID10811218.