 Open Educational Resources are free to access online and available for anyone to incorporate into their own course materials. If I wanted to reuse this figure from an OpenStacks textbook, I would simply add the attribution statement you see at the bottom, access for free at this OpenStacks.org URL. When I chose this image from the OpenStacks textbook, I looked at the section that the book provided on attribution, and that's where I learned the author's preferences for how to attribute and reuse properly this image. These instructions for reuse are based on the Creative Commons license. CCBI is the most typical of the Creative Commons licenses. This license allows for broad reuse of content with the understanding that the user will attribute the original author.