《旧唐书·列传·卷六十七》
贞元元年十一月，德宗在南郊祭祀先帝，震进入朝廷陪同祭祀。
贞元元年十一月，德宗亲祀昊天上帝于南郊，震入朝陪祭。
In November of the first year of Zhenyuan, Dezong offered sacrifices to the late emperor in the southern suburbs, and Zhen entered the court to accompany him.