《旧唐书·本纪·卷十二》
二十一日，扬州每年端午日进贡的在江心所铸造的镜子，幽州进贡的麝香，都免除不要进献。
己未，扬州每年贡端午日江心所铸镜，幽州贡麝香，皆罢之。
Twenty-first day, the Jiangsu mirrors created in the middle of the river that used to be offered as a tribute on the Dragon Boat Festival every year and the musk that used to be offered as a tribute from Yuzhou, was all exempt from being presented to the court.