[Photo provided to China Daily]

"The images of the flying Apsaras have changed over more than a 1,000 years. The earliest images seem very rugged and strong, but in the Tang Dynasty, flying Apsaras in the frescoes seem very gentle and gorgeous, more in keeping with a modern aesthetic standard," says Ding.

Dunhuang was a very important point on the Silk Road connecting China, the Middle East and Europe. And, in the Mogao Grottoes, archeologists have found silver coins from Persia.

Among the illustrations in the book is the image of a blond Apsara.

The book also contains short simple information explaining the origins and development of flying Apsaras in the Dunhuang frescoes.

Also, most of the 26 illustrations in the books come from frescoes that are not open to the public.