| The first window from the right gives a view of Umar's grave | Donner, Fred, The Early Islamic Conquests, Princeton University Press, 1981 |
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| by Shaykh Sayyed Muhammad bin Yahya Al-Husayni Al-Ninowy | Madelung, Wilferd, The Succession to Muhammad, Cambridge University Press, 1997 |
| Bonner "Umar" in Encyclopedia of Islam CD-ROM Edition v | |
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