《汉书·志·食货志下》
一百多年后，到周景王的时候他担忧钱太轻，准备改为铸造大钱，单穆公说： 这样不行。
其后百余年，周景王时患钱轻，将更铸大钱，单穆公曰： 不可。
More than 100 years later, when King Jing of Zhou, he was worried that the money was too light and prepared to cast big money instead. Shan Mugong said: This will not work.