Thomas A. Carlson (ed.), "Gwerkel" in last modified January 14, 2014, http://syriaca.org/place/2309
    
        
            
                
                    Gwerkel
                    ʻGurgel’
                    
          
                    http://syriaca.org/place/2309
                    
                        David Wilmshurst
                        The Ecclesiastical Organisation of the Church of the East, 1318-1913
                        100, 111, 123, 349, 350, 352