1. Simon Franklin and Jonathan Shepard, The Emergence of Rus, 750-1200 (1996), pp. 7-10.

2. Kevin Alan Brook, The Jews of Khazaria, 2d ed. (2006), p. 97; «The Letter of Joseph the King», in Jacob Rader Marcus, ed., The Jew in the Medieval World, rev. ed. (1999), pp. 227–228.

3. Kennedy (2004), Prophet and the Age, pp. 110–111.

4. al-Tabari, History, vol. 26, p. 72.

5. Kennedy, Prophet and the Age, p. 123.

6. Sicker, p. 27.

7. Ahmed ibn Mohammed al-Makkari, The History of the Mohammedan Dynasties in Spain, trans. Pascual de Gayangos (2002), pp. 95–96.

8. al-Tabari, History, vol. 27, pp. 172–174.

9. Arthur Wollaston, The Sword of Islam (1905), p. 130.

10. al-Tabari, History, vol. 28, p. 238; Sicker, p. 29.

11. M. A. Shaban, Islamic History (1976), p. 12.

12. Hodgson, Venture of Islam, vol. 1, pp. 286–287; al-Tabari, vol. 1, History, vol. 28, pp. 124ff; Shaban, p. 10.

13. Hodgson, Venture of Islam, vol. 1, p. 287.