- The Church in the Shadow of the Mosque: Christians and Muslims in the World of Islam (Jews, Christians, and Muslims from the Ancient to the Modern World)
- The Bible in Arabic: The Scriptures of the "People of the Book" in the Language of Islam
- The Beginnings of Christian Theology in Arabic: Muslim-Christian Encounters in the Early Islamic Period (Variorum Collected Studies Series, 746)
- A Treatise on the Veneration of the Holy Icons
- Syriac Writers on Muslims and the Religious Challenge of Islam