《资治通鉴·唐纪·唐纪五十七》
庚辰，成德监军上奏朝廷，称王承宗病重，由他的弟弟王承元暂时代理留后。同时，把王承元请求任命节度使的表奏上报朝廷。
庚辰，监军奏承宗疾亟，弟承元权知留后，并以承元表闻。
Gengchen, the Chengde supervisor reported to the court that Wang Chengzong was seriously ill and that his younger brother Wang Chengyuan was temporarily acting as the acting lieutenant. At the same time, Wang Chengyuan's request to appoint Jiedushi was reported to the court.