The electronic Sibu Congkan is a fully searchable collection of the authoritative editions of the 504 original and historical monographs (3,134 volumes) published by the Commercial Press in 1919-1936. Holdings span Song, Yuan, Ming and Qing Dynasties including early manuscripts and rare prints (antiquarian, out-of-print books). Original collection used photolithography, which resulted in better editions than any then-available typeset editions.
The electronic Sibu Congkan is based on the Shanghai Hanfen Lou version kept in the Peking University Rare Books Collection. With the full coverage of the 3 series published in the year 1922, 1932 and 1936 respectively, it reaches up to 232,478 pages and 90 million characters. Each series is traditionally categorized into Classics (jing 经), History (shi 史), Philosophy (zi 子), and Literary Collections or belles lettres (ji 集).