《北史·本记·卷二》
初六，放下辎重物品，以轻骑兵奇袭蠕蠕，把军队分为四路。
甲辰，舍辎重，以轻骑袭蠕蠕，分军为四道。
On the 6th of the month, they set down their baggage and supplies and made a surprise cavalry raid on the Rouran. The army was formed into four units.