《元史·列传·卷七十一》
郴州位于楚之上流，奚谷洞徭獠往来于民间，怕其强悍、狡猾，不敢与他们进行贸易，都中予以恩泽，施以威严，于是大家都心悦诚服。
郴居楚上流，溪洞徭獠往来民间，惮其强猾，莫敢与相贸易。都中煦之以恩，慑之以威，乃皆悦服。
Chen Prefecture was located in the upper reaches of the Chu River. The Yao and Liao minority peoples of Xigu Cave often travelled around the region. People were afraid of their strength and cunning and dared not trade with them. Du showed them kindness and authority, so they all submitted willingly.