《资治通鉴·汉纪·汉纪五十七》
辽西乌桓酋长蹋顿的势力尤其强盛，受到袁绍的厚待，因此袁尚兄弟去投奔蹋顿。蹋顿屡次派兵入塞抢掠，想帮助袁尚恢复旧有的疆土。
辽西乌桓蹋顿尤强，为绍所厚，故尚兄弟归之，数入塞为寇，欲助尚复故地。
The influence of Liaoxi Wuhwan chieftains Tatun was especially powerful, and he received Yuan Shao's favors, so Yuan Shang's brothers went to seek refuge with Tatun. Tatun sent troops into the border to loot for many times, wanting to help Yuan Shang regain his old territory.