LHASA, Feb. 19 (Xinhua) -- About 13,700 ancient books have been registered in southwest China's Tibet Autonomous Region after a wide survey across the region starting from 2009, the regional ancient book protection center said Tuesday.

So far, the survey has covered 1,160 ancient book collecting sites, including monasteries, museums, universities and individual homes.

In addition to the survey, Tibet has also launched the digital protection of ancient books and restoration of worn-out books.

Palbar Tsering, deputy librarian of the regional library, said the survey on ancient books was scheduled for completion in 2020.

Tibet is home to many ancien Tibetan books, mainly preserved in monasteries. The number of the ancient Tibetan books in the region accounts for about two-thirds of such books in the country.