《资治通鉴·唐纪·唐纪五十一》
张建封去世后，李藩回扬州。杜兼以不实之辞奏陈李藩在张建封去世之际动摇军心，德宗大怒，暗中颁诏命令杜佑将李藩杀掉。
建封薨，籓归扬州，兼诬奏籓于建封之薨摇动军情，上大怒，密诏杜佑使杀之。
After Zhang Jianfeng passed away, Li Fan returned to Yangzhou. Du Jian composed an untruthful letter to the court accusing Li Fan of stirring up the army at the time of Zhang Jianfeng's death, greatly angering Emperor Dezong, who secretly issued an edict ordering Du You to execute Li Fan.