《梦溪笔谈·故事一》
之后还有制书说： 宰臣刘昫，右，可以兼任三司事宜，应该让中书门下依此来施行。
其后有制书曰： 宰臣刘昫，右，可兼判三司公事，宜令中书门下依此施行。
Following is the system document: Prime Minister Liu Xu, right, can concurrently take care of the roles of Sansi, Zhong Shu Men Xia should implement it accordingly.