Manual de referencia de BASH - https://www.gnu.org/software/bash/manual/bashref.html
Man pages online - http://ss64.com/bash/
Bash para principiantes - http://www.tldp.org/LDP/Bash-Beginners-Guide/html/
Cheatsheet de redireccion - http://www.catonmat.net/download/bash-redirections-cheat-sheet.pdf
BASH scripting - http://tldp.org/LDP/abs/html/
Juego para practicar - http://overthewire.org/wargames/bandit/