Xuan Zhong Ji(Record of Mysterious Creatures): A work by the famed recorder of the supernatural and bizarre, Guo Pu of the Jin Dynasty, 3-4th Cent CE. although the work was lost early on, descriptions and parts are transmitted in compendia such as the Zui We Zong Mu by Wang Yaochen of the Northern Song and the Yuan Pan Lin of the Qing period (includes a portion of the missing book in the "Shi Zhong Gu Yi Zong Shu" section). And the "Gu Xiao Shuo Gou Shen" has a portion, with many accounts of strange creatures.
Celestial Fox: In the above Xuan Zhong Ji, the citation in Zhongguo Shenhua Chuanshuo Cidian, Shanghai 1985, reads almost word for word from the novel; Feng Menglong copied it straight out of a recorded portion of the Xuan Zhong Ji.
Xian Ping Reign... : 998 CE, in the Northern Song