If you are modifying an open textbook, you may want to find additional resources to use in your textbook. Ideally, content licensed with a CC-BY license provides the most flexibility for reuse, so we recommend trying to find content for reuse with that specific CC-BY licenses. If you are planning to make modifications to the resource, you will want to avoid any CC material that has the -ND (No Derivative) attribution as this content can be reused, but not modified.
If you are looking for Creative Commons licensed content, you can try the following services and search engines.

• Search Google using the Advanced search and limit the search to only return CC licensed material
• Use the Creative Commons search engine to search for images & photos on the following sites:
  • Flickr (photos and short videos)
  • Wikimedia Commons (photos, images, charts, graphs)
  • Soundcloud and CCMixter (audio)
  • YouTube (video)
• Search open academic journals for CC licensed materiel such as:
  • PLOS (Public Library of Science)
  • BioMedCentral
  • Other science journals
• Search open educational repositories like:
  • SOLR (BC higher ed and government material released under CC licenses)
  • Connexions
  • Merlot
  • OERCommons
  • Internet Archive

There are many more places to find open resources. A comprehensive list of openly licensed repositories is located in the OER Handbook for Educators, including some subject area specifics.