《明史·志·卷六十七》
不久杨一清因为触犯宦官刘瑾而被罢免。所修筑的边塞城墙仅四十多里而已。
旋以忤中官刘瑾罢，所筑塞垣仅四十余里而已。
Shortly afterwards, Yang Yiching was dismissed for offending the eunuch Liu Jin. The border city walls built were only over forty miles long.