《北齐书·列传·卷四十六》
僧人道研是济州僧侣首领，有大批资财，在郡中有很多产业，常常被郡县征税。
道人道研为济州沙门统，资产巨富，在郡多有出息，常得郡县为征。
Monk Daoyan was the leader of the Buddhist monks in Jizhou. He had a lot of money and many properties in the county, and the county and county often levied taxes on him.