《旧唐书·列传·卷三十七》
魏玄同因自己担当了选拔人才的职责，担心不能很好运用选人定职之术，就在这方面写了很有价值的书面意见上呈皇上，内容大义是：
玄同以既委选举，恐未尽得人之术，乃上疏曰：
Wei Xuantong gave presentations to the emperor on his views because he had been given the task of selecting and recommending candidates for government posts. He was worried he would not be able to apply the ranking of candidates for their posts appropriately; its main tenets were: