《魏书·列传·卷二十九》
丹谷、清廉两处道路险阻不通，朝廷以源子恭为当郡别将。
丹谷、清廉二路险涩不通，以子恭为当囗郡别将。
The roads of Danggu and Qinglian were dangerous and impassable, and the imperial court appointed Yuan Zigong as a Separate General of the county.