《宋书·列传·卷七十四》
拓跋焘给臧质写了一封信说： 我军现在派的战士，都不是我们鲜卑族人，城的东北是丁零人和东胡人，城南是陕西的氐族和羌族人。
焘与质书曰： 吾今所遣斗兵，尽非我国人，城东北是丁零与胡，南是三秦氐、羌。
Tuoba Tao wrote a letter to Zang Zhi and said: The soldiers we are sending now are not all Xianbei people. The northeast of the city is guarded by Dingling and Donghu people, and the south of the city is guarded by Di and Qiang people from Shaanxi.