《北史·列传·卷五十八》
武帝任命杜杲为御正中大夫出使陈国，陈说安定边境罢兵安民之意。
武帝授杲御正中大夫，使陈，论保境息人之意。
Emperor Wu appointed Du Gao as a doctor of Yuzheng Zhongda to go to the state of Chen, explaining that he wanted to stabilize the border, cease war and appease the people.