Black, Jeremy (2005). The Atlas of World History. American Edition, New York: Covent Garden Books. σελίδες 65, 228. ISBN978-0-7566-1861-2. This map varies from other maps which are slightly different in scope, especially along the Mediterranean and the Black Sea.
Houtsma, Martin Theodoor (1911) «Seljūks» στο: Chisholm, Hugh, επιμ. Εγκυκλοπαίδεια Μπριτάννικα24 (11η έκδοση) Cambridge University Press, σελ. 608–611
Maximilian Otto Bismarck Caspari (1911). "Theodosius (emperors)". In Chisholm, Hugh (ed.). Encyclopædia Britannica. 26. (11th ed.), Cambridge University Press. pp. 770-771.
Edmund Curtis (1911). "Robert Guiscard". In Chisholm, Hugh (ed.). Encyclopædia Britannica. 23. (11th ed.), Cambridge University Press. pp. 400-401.
Bréhier, Louis René. (1912). "Turkish Empire". In Herbermann, Charles (ed.). Catholic Encyclopedia. 15. New York: Robert Appleton Company.