What reference ancient books were there in Sui Dynasty?

Liang Shu, Chen Shu, Zhou Shu, Beiqi Shu and Sui Shu compiled in the early Tang Dynasty are all biographies with no ambition. In order to cooperate with it, The History of the Five Dynasties was compiled in a unified way, initially as a separate book, and later as Sui Shu.

Sui Shu Astronomical Calendar records the achievements and schools of famous astronomers and historians since Wei and Jin Dynasties, especially in the Southern and Northern Dynasties, and compares and comments them. Zu Chongzhi's research on pi, Zhang Zixin's and Liu Zhuo's exposition of "increasing daily surplus and shrinking daily" and the changes of weights and measures since Han and Wei Dynasties are recorded in detail.

Based on the geographical situation of Yang Di the Great in the fifth year (609), Geographical Records of Sui Shu records the household registration of counties, the situation of mountains and rivers, the establishment and evolution, and the customs and products of various regions, and provides important information about the traffic situation at home and abroad at that time. The geographical situation before the Sui Dynasty is only explained in the notes. The records of Sui events in Shihuozhi and Criminal Law Zhi are also more detailed, such as land, household registration, tax system, currency status, etc., which are simpler in other dynasties than in Sui Dynasty.

Chronicle of Criminal Law lists the compilation of five generations of legal books, and only the legislation in Sui Dynasty destroyed the law. There are three volumes of Le Zhi, in which Zheng Yi recorded seven songs by Su Zhipo, a Qiuci native, which became the source of Yan Yue in the Tang Dynasty. This paper introduces the origin, songs and musical instruments of Nine Songs of Yang Di Ji, which are important historical materials for cultural exchanges between China and foreign countries. Based on the book catalogue of Guandi Temple in the Eastern Jin Dynasty in Sui Dynasty, Classic Historical Records classifies all books into four categories: classics, history, zi and Ji, records the preservation and loss of ancient books at that time, and gives a general description of various academic sources, so as to investigate the ancient books in Han and Sui Dynasties. In addition, Emperor Yangdi gave preferential treatment to courtiers, rewarded fields and handmaiden, and was unwilling to give the land of the hero to the people. The grain and silk reserves in the treasury of the Sui Dynasty can be used for decades, but the servitude is still very heavy, the servitude is frequent, and the criminal law is harsh, so the working people are forced to constantly fight against it. This kind of important information is recorded in Biography of Sui Shu and Food and Criminal Law.