Bash Idioms: Write Powerful, Flexible, Readable Shell Scripts
Carl Albing & J P Vossen
Nmap Network Scanning
Gordon Lyon
Linux iptables Pocket Reference
Gregor N. Purdy
Mastering Linux Administration
Alexandru Calcatinge & Julian Balog
Cyber Security and Network Security
Sabyasachi Pramanik & Debabrata Samanta & M. Vinay & Abhijit Guha
Linux Bible (10th edition)
Christopher Negus
GitHub For Dummies
Sarah Guthals & Phil Haack