《资治通鉴·后汉纪·后汉纪三》
援兵还没到，南汉人已经攻占贺州，并在城外挖了大陷阱，覆盖竹席，加上土，下面设置了机关，从壕沟中挖洞通到阱里。
未至，南汉人已拔贺州，凿大阱于城外，覆以竹箔，加土，下施机轴，自堑中穿穴通阱中。
Before the reinforcements arrived, Nan Han had already captured Hezhou, and dug a large trap outside the city, covered it with bamboo mats, and added soil, and set up traps underneath, and dug a hole from the trench to the well.