《旧唐书·本纪·卷二十》
二月初一，太原李克用率军进攻镇州，军队到达井陉，王害怕，再次向幽州求救。
二月庚午朔，太原李克用以兵攻镇州，师出井陉，王镕惧，再求救于幽州。
On the first day of February, Li Keyong brought an army with him to attack Zhenzhou. The army arrived in Jingxing and Wang Rong was frightened and sought help from Youzhou once more.