Springer has dozens of book series in mathematics, they allow downloads of chapter or whole books
Access to electronic editions of journals and electronic books to which Penn State University Libraries subscribes, published by a company called Springer-Verlag. Journals cover the fields of chemistry, computer science, economics, engineering, environmental sciences, geosciences, life sciences, mathematics, medicine, and physics. Coverage: 1996-present. Updates: Continuous
has many older mathematics books out of copyright, and some Penn State books accessible to us
Sponsored by the libraries of the Committee on Institutional Cooperation, the University of California, and other partners, HathiTrust is a repository of digitized materials in all disciplines. Its content--primarily scanned books and journals-- may be searched via authors, titles, subjects, and other data elements.
Duxiu has 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 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).
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.