Omar Khayyam ; Barelvī, Sayyid Alt̤āf ʻAlī 1905-1986 ; Fahmī, Abūlmakārim Salīmullāh (1961) Ḥakīm ʻUmar K̲h̲ayyām. Akaiḍmī āf Ejūkeshnal Rīsarc. ISBN: .