《容斋随笔·卷十·战国自取亡》
虽然说有地势上的优势，并且善于用兵，因此百战百胜。但根据我的考察，实际上六国也有导致灭亡的内部原因。
虽云得地利，善为兵，故百战百胜，以予考之，实六国自有以致之也。
Although it is said that it has a geographical advantage and is good at using troops, it has won every battle. But according to my investigation, in fact, the Six Kingdoms also had internal reasons for their demise.