《魏书·列传·卷九十一》
太延五年，世祖向西讨伐沮渠牧犍，宜都王穆寿辅助景穆帝留守京师，长乐王嵇敬、建宁王拓跋崇率二万人镇守漠南，以防备蠕蠕来犯。
五年，车驾西伐沮渠牧犍，宜都王穆寿辅景穆居守，长乐王嵇敬、建宁要王崇二万人镇漠南，以备蠕蠕。
In the fifth year of Taiyan, the Ancestor campaigned westward against Juqu Mujian, King Musho of Yidu assisted Emperor Jingmu in guarding the capital, while King Jijing of Chang’le and King Tuoba Chong of Jianning led 20,000 men to guard the Mobei region and prevent the Rouran from invading.