《资治通鉴·汉纪·汉纪四十三》
尚书仆射虞诩上书说： 安定郡、北地郡、上郡，山川险要，沃野千里，土地适合畜牧，河水可以灌溉农田和运输粮秣。
尚书侦射虞诩上言： 安定、北地、上郡，山川险厄，沃野千里，土宜畜牧，水可溉漕。
The Shangshu servant shoot Yu Xu wrote a letter saying:安定郡, Beidi 郡, Shangjun, where the mountains and rivers are precipitous, are fertile for thousands of miles, and the land is suitable for animal husbandry. The river water can irrigate farmland and transport grain.