Why Open Education by David Blake is licensed under CC BY 3.0.
Section 78052 of California Education Code defines Open Educational Resources (OER) as:
“high-quality teaching, learning, and research resources that reside in the public domain or have been released pursuant to an intellectual property license that permits their free use and repurposing by others, and may include other resources that are legally available and free of cost to students. Open educational resources include, but are not limited to, full courses, course materials, modules, textbooks, faculty-created content, streaming videos, tests, software, and any other tools, materials, or techniques used to support access to knowledge.”