《辽史·本纪·卷十七》
三月初一，详稳萧匹敌自辽东还，称言其都统萧孝穆在离城四面各约五里的地方筑修城堡以围困大延琳。
三月甲寅朔，详稳萧匹敌至自辽东，言都统萧孝穆去城四面各五里许，筑城堡以围之。
On the first day of the third month, Xiao Pidi, the director of the Privy Council, returned from Liaodong and claimed that his commander, Xiao Xiaomu, had built castles around Dayanlin, about five miles from the city on all sides.