《资治通鉴·隋纪·隋纪六》
屈突通率军驻扎在河阳，宇文述率军跟随其后。杨玄感向李子雄问计，李子雄说： 屈突通精通军事，一旦他们渡过河来，那就胜负难分了，我们不如分兵抗击。
屈突通引兵屯河阳，宇文述继之，玄感问计于李子雄，子雄曰： 通晓习兵事，若一得渡河，则胜负难决，不如分兵拒之。
Qu Tutong stationed his army in Heyang, and Yu Wenshu led his army to follow him. Yang Xuangan asked Li Zixiong for advice, and Li Zixiong said: Qu Tutong is proficient in military affairs. Once they cross the river, it will be difficult to tell the outcome. We might as well divide our troops to fight against it.