《隋书·列传·卷八》
当时，江都失败的消息也传来了。杨庆得到了李密的书信，于是投降李密，改姓郭。
于时江都败问亦至，庆得书，遂降于密，改姓为郭氏。
At this time, news arrived that Jiangdu had fallen. Yang Qing received Li Mi's letter, so he surrendered to Li Mi and changed his surname to Guo.