《资治通鉴·汉纪·汉纪七》
估计土地没有比以前减少，而统计百姓的人口也没有比以前增加，按平均每人占有的耕地来计算，现在比古代还要多；但百姓的粮食却严重缺乏，造成这种失误的根源在哪里？
夫度田非益寡，而计民未加益，以口量地，其于古犹有馀，而食之甚不足者，其咎安在？
It is estimated that the land has not decreased compared to the past, and the number of people has not increased compared to the past. Calculated by the average cultivated land per person, it is now more than in ancient times; however, the people seriously lack food, where does the source of this mistake come from?