《辽史·本纪·卷九》
乾亨元年春正月初五，派挞马长寿出使宋国，责问兴师讨伐刘继元的原因。
鵩乾亨元年春正月乙酉，遣挞马长寿使宋，问兴师伐刘继元之故。
On the fifth day of the first lunar month in the first year of Qianheng, he sent Ta Ma Changshou as an envoy to the Song Dynasty, asking for the reason of commanding the troops to attack Liu Jiyuan.