2. Warring States policy. National historical works, also known as national policies. It recorded the major events of Western Zhou Dynasty, Eastern Zhou Dynasty, Qin Dynasty, Qi Dynasty, Chu Dynasty, Zhao Dynasty, Wei Dynasty, Han Dynasty, Yan Dynasty, Song Dynasty, Wei Dynasty and Zhongshan, about 240 years ago.
3. Purple Tongzhi Sword. A multi-volume chronological history book edited by Sima Guang in the Northern Song Dynasty, with 294 volumes, took 19 years to complete. Mainly based on time and events, it began in the 23rd year of Zhou Weilie (403 BC) and ended in the 6th year of Xiande, Zhou Shizong after the Five Dynasties (959 AD), covering the history of 16 dynasties and 1362 years.