Practical Digital Forensics
Richard Boddington
Hacking - The art of exploitation
Jon Erickson
Linux Firewalls
Michael Rash
Quick Start Guide to Penetration Testing
Sagar Rahalkar
Effective DevOps
Jennifer Davis & Ryn Daniels
sed & awk
Dale Dougherty & Arnold Robbins
Linux iptables Pocket Reference
Gregor N. Purdy