Fatwa dan ijtihad Umar bin Khaththab : ensiklopedia berbagai persoalan fiqih - al-Halawi, Muhammad'Abd al-'Aziz; Wasmukan; Abdullah, Zubeir Suryadi (Surabaya : Risalah Gusti, 1999)
Keywords: 'Umar ibn al-Khattab, -- Caliph, -- d. 644; Fatwas; Islamic law -- Interpretation and construction