Existence (Al-Wujud) and its relation to quiddity (Al-Mahiyyah) in the later Ash'arite Kalam : with special reference to 'Adud Al-Din Al-Ijis's Al-Mawaqif and Al-Sayyid Al-Sharif 'Ali Al-Jurjani's Sharh Al-Mawaqif - Mohd Zaidi bin Ismail (International Institute Thought and Civilizition, International Islamic University Malaysia, 2005)