Robert Harry van Gent. Biography of al-Sūfī. "The Persian astronomer Abū al-Husayn 'Abd al-Rahmān ibn 'Umar al-Sūfī was born in Rayy (near Tehrān) on 7 December 903 [14 Muharram 291 H] and died in Baghdād on 25 May 986 [13 Muharram 376 H]... the Persian astronomer Abū al-Husayn 'Abd al-Rahmān ibn 'Umar al-Sūfī who was commonly known by European astronomers as Azophi Arabus". University of Utrecht, Netherlands. Truy cập 2014-1-11
