《新唐书·列传·卷四十九》
姚、宋可说是具有先见了。然而，有唐三百年间辅弼大臣是不少的，而人们只前称 房、杜 ，后称 姚、宋 ，这是什么原因？
然唐三百年，辅弼者不为少，独前称房、杜，后称姚、宋，何哉？
Yao and Song can be said to have foresight. However, there were many ministers and ministers who assisted the Tang Dynasty for three hundred years, and why do people only call Fang and Du before and Yao and Song later?