Ovid E-books
Ovid provides high quality scholarly books from worlds most prestigeous publishers in a range of discliplines.
BookShelf
Bookshelf provides free online access to books and documents in life science and healthcare
DOAB (Directory of Open Access Books)
Directory of Open Access Books is a joint service of OAPEN.
Free Books 4 Doctors
FreeBooks4Doctors provides online medical books/literature to doctors and those in the medical professions.