《资治通鉴·唐纪·唐纪五十》
宣武节度使刘玄佐威严而有谋略，每当李纳的使者到来时，刘玄佐便深深地结纳他们，所以经常能够得知李纳的秘事，预告做好防备，李纳畏惧他。
宣武节度使刘玄佐有威略，每李纳使至，玄佐厚结之，故常得其阴事，先为之备。纳惮之。
Liu Xuansuo, Jiedushi of Xuanwu Circuit was formidable and resourceful. Whenever emissaries from Li Na arrived, Liu Xuansuo would treat them well with the intention of ingratiating himself with them, and so he was able to find out Li Na's secrets and prepare his own defenses beforehand, and so Li Na was afraid of him.