The books: bash for beginners & bash for advanced users
http://www.tldp.org/LDP/Bash-Beginners-Guide/html/index.html
http://tldp.org/LDP/abs/html/index.html
Brace Expansion
http://www.thegeekstuff.com/2010/06/bash-shell-brace-expansion/
Scripts avancés
https://dascritch.net/post/2018/01/08/En-20-lignes-pas-plus-%3A-g%C3%A9rer-les-options-d-appel-de-tes-scripts-bash