Licensing

This book is published under a Creative Commons BY-SA license (CC BY-SA) version 4.0. This means that this book can be reused, remixed, retained, revised and redistributed as long as appropriate credit is given to the author. If you modify the original version of this open textbook, you must redistribute all new versions of this open textbook under the same license - CC BY-SA. https://creativecommons.org/licenses/by-sa/4.0/.