《新五代史·本纪·晋本纪第八》
十九日，赵德钧及其子延寿叛唐来归降，契丹给他们戴上枷锁随同北归。
甲戌，赵德钧及其子延寿叛于唐来降，契丹锁之以归。
On the 19th, Zhao Dejun and his son Yanshou defected from Tang and surrendered, and the Khitan put them in shackles and took them north.