Ugo Zanetti and Nathan P. Gibson (eds.), "Medieval Apocalypses as Historical Sources" in last modified January 4, 2016, http://syriaca.org/bibl/1056
    
        
            
                
                    
                        P.J.
                        Alexander
                    
                    Medieval Apocalypses as Historical Sources
                    http://syriaca.org/bibl/1056
                
                
                    American Historical Review
                    
                        1968
                    
                    73
                    997-1018