Cambridge Open
https://www.cambridge.org/core/what-we-publish/open-access
eBooks@Adelaide
https://ebooks.adelaide.edu.au
JSTOR Open
http://about.jstor.org/open-access
Oxford Open - Books
https://global.oup.com/academic/open-access/titles/?lang=en&cc=tr
Springer Open - Books
http://www.springeropen.com/books