It was rediscovered last year when researchers checked the inventory of a museum in Qufu, and was selected for the directory this time. As the original stele in Beijing has been partially eroded due to its age, this replica on paper is hugely significant for academic reference.

According to Chen from the Ministry of Culture and Tourism, it is estimated that China has more than 30 million copies of ancient books, and about 90 percent of them have been registered in details in the national survey.

China has also established 12 national-level restoration centers of ancient books to rescue the aging pages. And 203 libraries, museums, universities, and other conservation institutions-including 23 newly titled this month-are listed as national-level key venues on protection of ancient books.

Digitized copies of about 72,000 varieties of ancient books have been uploaded to a national database for public access. Chen also says more ancient Chinese books, which were lost to overseas during war or for other historical reasons, can be "brought home" in digital forms to fill in the gaps in domestic studies.