Unix and Linux System Administration and Shell Programming

Implementing SSH: Strategies for Optimizing the Secure Shell

CentOS System Administration Essentials

Power User Guide: Linux Tricks, Hacks and Secrets [Volume 1]: Bash Systems Reference (2019 Edition)

Red Hat Linux Internet Server

Learn Kali Linux 2019: Perform powerful penetration testing using Kali Linux, Metasploit, Nessus,...

Korn Shell / ksh: Essential Programs for Your Survival at Work: Book 1 in the Rosetta Stone Serie...