8 copies.
According to information from Sina.com, there are eight books by Liu Bowen that reveal the secrets of heaven, including Liu Bowen’s revelations of secrets, Hu Xueyan’s business with people all over the world, He Shen’s Cursed Talented Officials, Zeng Guofan’s Pilgrimage Road alone, Cao Cao, Liu Yan, Wei Zheng, Guan Zhong.
Liu Bowen's Secret of the Sky is a book published by Chinese Publishing House on September 1, 2017. The author is Liu Suping.