LICENSE: This is the entire textbook as a PDF file. When you purchase it, you get the right to use the book without limit in your school. This includes sharing it with your students on any internally accessible site, such as a closed Google classroom, Wiki, Moodle, etc. The posting of materials on publicly accessible sites is not allowed. It is also not allowed to share the book outside of your school. This license has no time limit: purchase it once and use it for as long as you want, with as many students as you have.
