Qin Shihuang burned books to bury Confucianism, and the historical books of the Warring States period were basically not preserved because of their small circulation compared with other works. Therefore, Sima Qian wrote Historical Records to describe the major events in the Warring States period, basically based on the official history books of Qin State and the works of military strategists. The former account is too simple, while the latter is often full of fictional stories, so Sima Qian himself thinks that the historical events in the Warring States period are difficult to verify.
However, after the excavation of bamboo annals, people got new historical materials about the Warring States period and learned a lot of new contents. Therefore, compared with historical records, many mistakes can be corrected, especially the confusion about Chronicles of Six Kingdoms.
There are differences between the ancient version and the present version of Zhushuzhi. The chronology of bamboo books unearthed in the Western Jin Dynasty was lost in the Song Dynasty. Later, people compiled and published new bamboo annals. However, historians have found that many contents in the annals of bamboo books handed down from ancient times are wrong, so its historical value is greatly reduced. So what was first excavated was called Chronology of Ancient Bamboo Books, and what was handed down was called Chronology of Modern Bamboo Books.
Because the chronology of ancient bamboo books is very important in the study of Warring States history, historians want to reproduce it as much as possible. The reason why this can be done is that although the chronology of ancient bamboo books has been lost, its fragments are often quoted in other historical materials before the Song Dynasty. Because of this, the chronicles of ancient bamboo books have been studied a lot. For example, Wang Guowei mentioned on the first floor devoted himself to its textual research.