Xian () occurs in the Chunqiu Fanlu, Fengsu Tongyi, Qian fu lun, Fayan, and Shenjian; xian () occurs in the Caizhong langji, Fengsu Tongyi, Guanzi, and Shenjian.
The concept of Xian () is explored in various ancient texts such as the Chunqiu Fanlu, Fengsu Tongyi, Qian fu lun, Fayan, and Shenjian; xian () is also referenced in other important works like Caizhong langji, Fengsu Tongyi, Guanzi, and Shenjian.