The following resources might be interesting if you'd like to go deeper into the subjects of this chapter:
- The case statement: http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_07_03.html
- Brace expansions: http://wiki.bash-hackers.org/syntax/expansion/brace
- The Linux Documentation Project on loops: http://www.tldp.org/LDP/abs/html/loops1.html