《梦溪笔谈·官政一》
宋代云梯食盐的种类极多，以往史书所记载的，在周边少数民族地区已自有十多种，中原地区所出产的也不下几十种。
盐之品至多，前史所载，夷狄间自有十余种；中国所出，亦不减数十种。
There are many kinds of salt in the Song Dynasty. According to historical records, there are more than ten kinds in the surrounding ethnic minority areas. There are also no less than dozens of kinds produced in the Central Plains area.