《旧唐书·本纪·卷十八》
又敕令 ：各道铸造的钱币，已经有先后顺序，须令旧钱流通，使绢帛的价值稍许增高。
又敕： 诸道铸钱，已有次第，须令旧钱流布，绢价值增。
Another imperial edict states that all the copper currency that has been cast in each circuit should first be circulated, and that the price of silk cloth should be increased slightly.