All these books are free to read: either they're distributed with a free license, or they're in the public domain.
These books are available in EPUB format - good for iBooks, Nook, Kobo.
keyword: Nonfiction – 247 free books.
James Boyle and Jennifer Jenkins
Chris Benner and Manuel Pastor
Sherri Melrose et al.
Alejandra Perez Nuñez et al.
Aya Homei and Michael Worboys