BEIJING, Dec. 10 (Xinhua) -- Scholars of China's Tsinghua University have deciphered five documents recorded on bamboo slips dating back to the Warring States period more than 2,000 years ago, according to a press conference in Beijing on Sunday.

"There are two documents on rituals, which was the first discovery of the pre-Qin period (pre-221 B.C.) books on rituals recorded in the bamboo slips of Warring States Period (475-221 BC) so far unearthed," said Huang Dekuan, director of the Research and Conservation Center of the university.

The university houses nearly 2,500 precious bamboo slips from the Warring States period. The university's research team has collated and studied the ancient documents since 2008.

They have released their research results every year since 2011, with 13 volumes of the annual report published, covering compiled documents on classics and history, politics, astronomy, mathematics, and others.

This year's collection covers the documents on the ceremonial dining system of the nobles as well as music and ideological literature.

Editor：Guo Lili