The CSIC Libraries have incorporated the IntechOpen resource in their collection  

http://sp.urici.csic.es/subjects/databases.php?letter=I

IntechOpen is a platform for peer-reviewed open access books that contains more than 3,350 books that can be read, shared and downloaded for free. Currently the platform has:

1,765 books of Physical Sciences, Engineering and Technology

538 books on Nature Sciences and Biology

1,134 books of Health Sciences

132 books of Social Sciences and Humanities