Limit your search as you normally would when selecting classes. Choose your subject (e.g. Biology, Art History), campus (e.g. East Los Angeles College), days of the week (e.g. Mondays), or any other criteria.
You're going to now limit to just search for classes that do not require students to purchase textbooks or other educational materials! Under "Class Search," there is an option to limit your results by "Class Search Type."
Choose, "Zero Textbook Cost (ZTC) - OER."
Click on "Search." Now all the classes you see will be ZTC/OER. You will NOT be required to purchase a textbook or other educational materials.