(3GdOYhI GdGSdGejI aj YgO GejQ GdeDefjf YeQ Hf GdNWGH (B/s - (3ZjWGS, MSfj eMeO GHQGgjes (Qaherah : al-Zahra' lil-I'lam al-'Arabi, 1995)
Keywords: 'Umar ibn al-Khattab, -- Caliph, -- d. 644 -- Contributions in Da'wah; Da'wah (Islam) -- History; Islamic Empire -- History -- 622-661