《魏书·列传·卷十二》
子勋失败，道固就派人送信归附魏国，显祖任命道固为安南将军、南冀州刺史、清河公。
子勋败，乃遣表归诚，显祖以为安南将军、南冀州刺史、清河公。
When Zixun was defeated, Daogu sent a message pledging allegiance to the Wei state, and the Emperor granted Daogu the titles of General Who Pacifies the South, Governor of Southern Jizhou, and Duke of Qinghe.