《资治通鉴·晋纪·晋纪三十三》
孟敏任沙州刺史时，提升李任效令。宋繇则为北凉王段业做事，任中散常侍。
及孟繁为沙州刺史，以暠为效谷令；宋繇事北凉王业，为中散常侍。
When Meng Min was the governor of Shazhou, he promoted Li Renxiao to be the governor of Xiaoling. Song You served as a constant attendant for the crown prince for the Northern Liang King, Duan Ye.