Google Books
Google Books provides full, free PDF scans (and web-viewable versions) of public domain books and magazines, free previews of some books and magazines under copyright, and the option to purchase digital editions of available items to save and read on Google Play, their e-reading platform. You can also find a local library based on your zip code that has the item available. Reader reviews of the items are available and you can contribute your own. Search for authors, titles, as well as keywords and Google will return results with matches in the title/text of the item. There are permalinks to available pages. Highly useful for finding items that contain your keywords in its text.
The SSH Open Marketplace is maintained and will be further developed by three European Research Infrastructures - DARIAH, CLARIN and CESSDA - and their national partners. It was developed as part of the "Social Sciences and Humanities Open Cloud" SSHOC project, European Union's Horizon 2020 project call H2020-INFRAEOSC-04-2018, grant agreement #823782.