A native of Qinghe (now Qinghe, Hebei Province). History of officials. Gongshu was written by Zhang Xu and passed down to Chu Changwen and Han Fangming. A taste of the book says: "Mountains, rivers, vegetation, and trees are reflected on the paper, and the sun, moon, and stars are reflected on the ruler and tablets." ("The Essence of the Book Garden, The Essentials of Book History, and the Secret of Linchi")