Library resources and open access materials are also acceptable materials to replace a commercial textbook for the purposes of this grant.
Library resources refers to books, chapters, articles, and other published materials that are included in the library's collections or subscriptions. These may be physical or digital.
Open Access usually refers to research books, chapters, or articles that have been published through typical scholarly processes, but the publisher has provided public online access at no cost, or allowed the author(s) to provide such access via self-archiving or an institutional repository. The larger Open Access movement includes other materials as well, such as software and data sets.
Let's discuss what library resources and open access materials have in common with OER:
That's about it. Library resources are free for students, but not for the library, and in the case of online databases or streaming film collections, individual items might be removed from the collection by the vendor when contracts change. Open Access are free to read and share, but may or may not allow copying, redistribution, or alteration.
Depending on the textbook you're attempting to replace, you may need to supplement an OER with library or OA resources, or make a reading list entirely from those materials. I just wanted to be clear on the distinction.
More links on libraries and OA: