《管子·八观》
估量敌国和盟国，了解君主的意志，考察农业的状况，看看人民财产是有余还是不足；存亡之国，就可以区别出来了。
计敌与，量上意，察国本，观民产之所有余不足，而存亡之国可知也。
By assessing the enemy and allied nations, understanding the monarch's will, and examining the condition of agriculture, we can see whether the people's wealth is abundant or insufficient; we can then distinguish between surviving and perishing nations.