《明史·列传·卷九十》
俺答诸部年年侵扰边关，贾应春说： 诸边之间没有互相通报侦察的情况，每逢敌寇入侵不能测知其向，而我们则每个戍所都得进行备战。
俺答诸部岁扰边，应春言： 诸边间谍不通，每寇入莫测其向，我则无所不备。
The several areas of Onan each year harassed the border, Jia Yingchun said: Between the several areas, they do not each report and scout conditions, each time the enemy invades, they cannot ascertain their direction, and we then have every garrison prepare for battle.