《尉缭子·分塞令》
中军和左、右、前、后各军，都有分配的营地，营地四周围以矮墙，不能互相来往。
中军、左、右、前、后军，皆有，方之以行垣，而无通其交往。
The central army and the left, right, front, and rear armies each have their assigned camps, and the camps are surrounded by low walls, and they cannot access each other.