Duxiu offers full-text searching to more than 3 million volumes of books on all subjects published in China. Users may view the first 15 pages of the book, and request document delivery (using tushuguan wenxian chuandi) for additional pages or specific chapters to be delivered via email. For a given book, there is a weekly request limit of 50 pages or 20% of the book (whichever is smaller). Online requests (document delivery) are typically fulfilled in a near instantaneous manner.