《资治通鉴·晋纪·晋纪四》
拓跋猗越过沙漠以北去巡视，借此向西攻打各国。经过了五年，投降归附他的有三十多个国家。
拓跋猗度漠北巡，因西略诸国，积五岁，降附者三十馀国。
Tuoba Yi crossed the desert to the north to patrol, taking advantage of this to attack various countries in the west. After five years, more than 30 countries surrendered to him.