《资治通鉴·晋纪·晋纪三十一》
拓跋向手下的各位将领询问瘟疫的蔓延与治疗情况，将领们回答说： 活着的十分之四五。 
珪问疫于诸将，对曰： 在者才什四、五。 
Tuoba asked his generals about the spread and treatment of the plague, and the generals replied: Four or five out of ten are alive.