The language retrieval field of the catalogue retrieval system of the National Library of China provides retrieval in these languages, namely Chinese, English, Russian, Greek and Hebrew. Because the National Library of China has inherited the royal collections of the past dynasties since the Southern Song Dynasty and the private collections of many famous artists since the Ming and Qing Dynasties, the earliest collection can be traced back to the Oracle bones in the Yin ruins more than 3,000 years ago. Special collections include more than 2.8 million copies of Dunhuang suicide notes, western region documents, precious ancient books, epigraphy rubbings, ancient maps, ancient books in minority languages, and famous manuscripts. Wen Jinge's Notes on Dunhuang, Zhao Zang, Yongle Dadian and Four Encyclopedias are called "the Collection of Four Academies" in the National Library, but as of June 9, 2022, only Chinese, English, Russian, Greek and Hebrew can be searched.