《后汉书·列传·乌桓鲜卑列传》
冬天，鲜卑进入上谷，进攻居庸关，朝廷再次征调边境各郡的部队、黎阳营的士兵、寻迹而射的士兵、步兵和骑兵共有二万人，把守各个要害地方。
冬、鲜卑入上谷，攻居庸关，复发缘边诸郡、黎阳营兵、积射士步骑二万人，屯列冲要。
In winter, the Xianbei entered Shanggu and attacked Juyong Pass. The imperial court once again conscripted troops from the border counties, soldiers from the Liyang Camp, tracking and shooting soldiers, infantry and cavalry, totaling 20,000 men, to guard the key areas.