Sixty-four volumes of The Integration of Ancient and Modern Books, each with 10,000 volumes and 40 catalogues, * * * has printed 5,020 volumes. Printing such a large encyclopedia is the first time in the history of our country, and because it is printed with copper movable type, it is a great event in the history of printing. The collection of ancient and modern books is arranged by category, and the collected materials are extremely rich, most of which are whole paragraphs, whole articles or whole works. Therefore, a large number of ancient books of Song, Yuan and Ming Dynasties have been preserved and circulated.