Four more books on the epic of King Gesar have been published, as part of efforts to preserve the 1,000-year-old story.

The Epic of King Gesar has about 200 episodes and is believed to be one of the world's longest epics. It tells how an 11th century Tibetan king conquered his enemies and helped ordinary people.

The epic has been passed down orally by singers, often illiterate herders or peasants from the Tibet autonomous region, the Inner Mongolia autonomous region and Qinghai province.

The four books are based on chants by three folk singers, says Tsering Phuntsog, the director of ethnic studies center at the Tibetan Academy of Social Sciences.

One book is about Tibetan mastiffs, two are about tribal wars during the King Gesar period, and the fourth is about how Gesar conquered a region and distributed gold to the people.

Each book comprises around 200,000 words, and they are part of a project called Exclusive Renditions of Folk Artists on King Gesar, which aims to publish 20 books, based on chants by 14 artists.

So far, 14 books have been published.

Work on the transcription, recording and videos of the stories started in 2009.
The epic of King Gesar was listed as part of the World Intangible Cultural Heritage in 2009.

Meanwhile, some of the books from the project are to be translated into Mandarin.