Feel free to make suggestions/corrections, or whatever you think it would be interesting to see in this document. I'll try to update it as soon as I can.
This documents comes with no warranty of any kind. and all that
Introduction to bash (under BE) http://org.laol.net/lamug/beforever/bashtut.htm
Bourne Shell Programming http://207.213.123.70/book/
https://www.cs.colostate.edu/wiki/mediawiki/images/b/be/Bash-reference.pdf