{"id":"001498955","type":"article","title":"The Citadel of al-Raqqa and Fortifications in the Middle Euphrates Area","publisher":"Bill","publisher-place":"Leiden","pages":"122-150","container-title":"Muslim military architecture in Greater Syria. From the Coming of Islam to the Ottoman Period","author":[{"family":"Heidemann","given":"Stefan."}],"issued":{"raw":"2006"}}