Use the ISBN of your current textbook to find free alternatives

 
Visit: Coolfored.org - On this site use the FIND section for looking at:
 
 
Do an ISBN search - enter YOUR current textbook (one that is fee based) to identify a list of suggested OER materials
Steps - Click here and scroll to bottom of page.
Enter the ISBN number in the appropriate search box
Locate an OER title for your use