《北史·本记·卷二》
诏令尚书左仆射安原等人在漠南屯守，以防备蠕蠕。
诏尚书左仆射安原等屯于漠南，以备蠕蠕。
Emperor Xiaowen of Northern Wei ordered minister of the left An Yuan and others to station troops in southern Mobei (i.e., the area south of the Mobei Desert) to defend against the Rouran.