《旧唐书·列传·卷一百零九》
元和七年，惠昭太子薨，穆宗当时为遂王，宪宗认为澧王年纪居长，又多内助，欲立遂王为皇位继承人，命崔群替澧王做辞让表。
元和七年，惠昭太子薨，穆宗时为遂王，宪宗以澧王居长，又多内助，将建储贰，命群与澧王作让表。
In the seventh year of the Yuanhe reign period, Crown Prince Huizhao passed away. Prince Muzong, who was at the time Prince Sui, was the eldest in age and also had more imperial consorts, hence Emperor Xianzong wanted to establish Prince Sui as the heir to the throne, and ordered Cui Qun to draft a letter of declination for Prince Li.