What is the earliest document in the world that systematically describes movable type printing?

Wang Zhen, a scientist in the early Yuan Dynasty, successfully made wooden movable type. He spent two years designing and instructing craftsmen to make more than 30,000 kinds of wooden movable type with pear wood and jujube wood, and printed a book "Jingdezhen County Records". In order to popularize wooden movable type printing, Wang Zhen wrote his method of making wooden movable type into a book "Making Movable Type Printing Calligraphy", attached to the back of agricultural books, and introduced his method of printing wooden movable type in detail. This book by Wang Zhen is the earliest document in the world that systematically describes movable type printing.