OASIS (Openly Available Sources Integrated Search) -- Developed by SUNY Geneseo’s Milne Library, an innovative new search tool that can access 52 different OER sources that contain more than 150,000 items. You can limit search results by license, type, subject, source, and reviews available. Content includes textbooks, courses and corresponding materials, interactive simulations, public domain books, audiobooks, modules, open access books, videos and podcasts.
Below are a few places to look for Open textbooks. If you can't find the perfect one, consider creating your own by pulling together parts from several textbooks plus your own unique materials.