Open Educational Resources (OER) are "teaching, learning, and research resources that reside in the public domain or have been released under an intellectual property license that permits their free use and re-purposing by others."
From The William and Flora Hewlett Foundation
OER materials are released under an open license granting permission for every one to:
OER include digital learning materials such as:
Click to download:
https://drive.google.com/file/d/1YTOYT1Lib5i7OVXu2o9eXDZupSo5CKzj/view