Buy the paperback on Amazon.
All eBook editions are DRM-free:
Kindle version on Amazon
Nook version on Barnes & Noble
iBook version for Apple/iOS
The Open Schoolhouse is a self-funded project. If you like it and wish to help spread the word, please consider purchasing a paperback copy for a friend, your local school, favorite teacher, or public library.
You may also help by writing an Amazon or Goodreads review. Reviews and ratings keep the book on the charts where more schools will discover and share it.