The Investiture of the Gods by Xu Zhonglin (1567-1619)

The Investiture of the Gods is a sweeping 100-chapter novel written in vernacular Chinese. It blends history, mythology, and folklore to retell the overthrow of King Zhao of the Shang Dynasty by Ji Fa of the Zhao Dynasty. One anecdote relates how King Zhao insults the goddess Nüwa. Nüwa sends the spirit Su Daji to bewitch King Zhao, who begins to neglect his country. This leads to his overthrow by Ji Fa, advised by his chancellor Jiang Ziya. Kuang has stated that The Investiture of the Gods is a major inspiration for The Poppy War. She draws many characters, such as Su Daji and Jiang Ziya, straight from the novel.

Japan’s Infamous Unit 731: First-hand Accounts of Japan’s Wartime Human Experimentation Program by Hal Gold (1996)

This book details the gruesome experiments undertaken by the Imperial Japanese Army’s most infamous medical unit, Unit 731. The first half of the book relates the unit’s history and its most shocking experiments. The second half is composed of firsthand accounts by Unit 731 members, who describe what it was like to experiment on fellow humans, what motivated them to do it, and why they decided to speak about their experience years later.