Building Internet Firewalls: Internet and Web Security
How Linux Works, 2nd Edition: What Every Superuser Should Know
Version Control with Git: Powerful tools and techniques for collaborative software development
Unix Power Tools
How to Hack Like a PORNSTAR: A step by step process for breaking into a BANK (Hacking the planet Book 1)
Learning the vi and Vim Editors: Text Processing at Maximum Speed and Power
Absolute FreeBSD, 3rd Edition: The Complete Guide to FreeBSD
sed & awk: UNIX Power Tools (Nutshell Handbooks)
The Linux Command Line, 2nd Edition: A Complete Introduction