《汉书·志·沟洫志》
这件事交给丞相、御史处理，丞相、御史说博士许商研究《尚书》，善于计算，能估计费用。
事下丞相、御史，白博士许商治。《尚书》，善为算，能度功用。
The matter was handed over to the prime minister and the imperial censor for handling. The prime minister and the imperial censor said that the doctor Xu Shang was well versed in the "Book of Documents" and was good at making calculations and could estimate the cost.