Researchers have discovered what is presumed to be the oldest existing copy of Sasi Chanyo, a historic Chinese book on agriculture originally published during the Tang Dynasty.

Yecheon County in North Gyeongsang Province announced on Thursday that a Kyungpook National University team was surveying a historic house in the area when it uncovered the copy, possibly a national treasure. 

The copy was printed using Korea's metal movable-types minted from the year of Gyemi in 1403. 
 
Sasi Chanyo, the account of seasonal customs, was published by a Chinese scholar of the Tang Dynasty during the tenth century. No original copies of the book have ever been found.