AMS Books Online - In addition to the print publications, the AMS makes selected titles available to the mathematical community by posting books online. AMS Books Online comprises bookmarked PDF files that can be downloaded by chapter and may include corrections that are not in the printed version.
Cornell University Library Historical Math Monographs - The Cornell University Library Historical Mathematics Monographs is a collection of selected monographs with expired copyrights chosen from the mathematics field. These were monographs that were brittle and decaying and in need of rescue.
University of Michigan Historical Mathematics Collection - The University of Michigan Historical Mathematics Collection is a growing library of books selected from the University of Michigan mathematics collection that have been digitized to improve access and to preserve the content of these books. All of the books in this collection were published in the 19th or early 20th century.