《旧五代史·后唐·列传十九》
常山一战，李嗣昭为帅，死于军中，任圜代理李嗣昭为军队总管，号令指挥和李嗣昭生前一样，敌人都不知道换了主帅。
常山之役，嗣昭为帅，卒于军，圜代总其事，号令如一，敌人不知。
In the Battle of Changshan, Li Sizhao was the commander, who died in the army. Ren Yuan acted as Li Sizhao's general manager of the army, and the orders were the same as those of Li Sizhao before his death, so the enemy did not know that the commander had changed.