Open Educational Resources (OER)

E-Books

• Directory of Open Access Books - It is a community-driven discovery service that indexes and provides access to scholarly, peer-reviewed open access books and helps users to find trusted open access book publishers.
• epubBooks - It is a large collection of public domain English books from the last five hundred years. They are in EPUB and Kindle MOBI formats.
• Hathi Trust Digital Library - It is a repository providing access to public domain and in-copyright content from a variety of sources, including Google, the Internet Archive, Microsoft, and in-house partner institution initiatives. 
• Project Gutenburg - It is a collection of books in the public domain, made available for convenient reading on digital devices completely for free. The books are in a variety of formats that are all copyright-free in the United States.
• Taylor & Francis Open Access eBooks - Explore Open Access eBooks published by Taylor & Francis, and discover content available across subject areas including economics, history, law, media & cultural studies, politics, sociology and more.
• United Nations iLibrary - It is an online collection providing easy access to thousands of books, reports, and journals created by the United Nations available for search, share, and download in one place.

E-Textbooks

• B.C. Open Collection  - It is Canada's open textbook initiative to make open textbooks available for online teaching and learning and was developed in British Columbia. It contains open textbooks on a variety of subjects from Art to Social Sciences.
• Bookboon - It is an online book publishing company based in London, United Kingdom. It offers PDF eBooks which can be downloaded for free. All books are exclusively written for Bookboon by professors from the world's top universities. Subjects range from business books to university textbooks.
• LibreTexts - It provides access to OER resources and a platform for faculty to curate and compile resources. LibreTexts is based at University of California, Davis. 
• Open Book Publishers - It is an open access academic book publisher based in the United Kingdom. It promotes open access for full academic monographs, critical editions and textbooks in the Humanities, Social Sciences, Mathematics and Science. All OBP books are peer-reviewed.
• OpenStax  - It is a nonprofit organization based out of Rice University and is one of the leading providers of OER textbooks. OpenStax textbooks are available as free downloads in PDF, Web, and EPUB formats. The textbooks are peer-reviewed, and openly licensed.
• Milne Open Textbooks - It is a catalog of open textbooks authored and peer-reviewed by SUNY faculty and staff. Formerly known as Open SUNY Textbooks.
• Open Textbook Library (OTL)  - It is part of the Open Textbook Network, founded by the University of Minnesota. It provides lists of open textbooks in a range of disciplines, accompanied by reviews from staff at academic institutions. 
• Wikibooks - It is a project for collaboratively writing open-content textbooks that anyone can edit. These books can be textbooks, annotated texts, instructional guides, and manuals.