《隋书·列传·卷二十》
一年多后，云州总管贺娄子干去世，皇上哀悼叹惜很久，因而对侍臣们说： 榆林是国家的重镇，怎能再得到像贺娄子干那样的人才去镇守呢？ 
岁馀，云州总管贺娄子干卒，上悼惜者久之，因谓侍臣曰： 榆林国之重镇，安得子干之辈乎？ 
More than a year later, the Governor General of Yunzhou, Helou Zigun, passed away. The emperor mourned and sighed for a long time. He asked his servants, "Yulin is a key military stronghold of the state. How can we find someone like Helou Zigun to guard it?"