《资治通鉴·唐纪·唐纪五十七》
穆宗在便殿召见崔群，说； 朕当年被立为皇太子，知道你曾有赞助的功劳。 
上曰： 朕升储副，知卿为羽翼。 
Emperor Muzong summoned Cui Qun to the side hall and said; I was established as the Crown Prince and know that you made some contributions.