Open educational resources
Open educational resources (OER) are educational materials which are licensed in ways that allow individuals and institutions to reuse, adapt and modify the materials for their own use. OERs can, and do include full courses, textbooks, streaming videos, exams, software, and any other materials or techniques supporting learning. (OER Foundation)
How to use OER
OER can be downloaded, embedded, re-used or adapted to suit particular teaching or learning activities, depending on the license.
Find open text books via these search sites: