You can use it to prepare your own material or to translate it to different languages.
It will be nice if you share modifications with the community though it is not a must.
A special thank you to @klaus who wrote the booklets and agreed to share the source with the community!
Hi Erel,
Thanks to Klaus for the useful work.
I could view the files source code online but didn't know how to download the booklets.. no link to save in local machine, or I am missing something.