Ubuntu LTS User Guide for IT Professionals: Practical System Administration, Security Hardening, and Real‑World Deployment Techniques.

Linux Kernel Development

LINUX FOR BEGINNERS: How to Master the Linux Operating System and Command Line from Scratch

Ubuntu Unlocked: The Complete Beginner’s Guide to Linux Freedom (The Developer's Guide series)

Linux Kernel Programming for System Engineers: A Hands-On Approach

Unlocking Lubuntu: From Basics to Advanced User: Lubuntu

The eBPF Project Workbook: Build Real Kernel Programs in Networking, Metrics & Security

SELinux Security Projects Unleashed: Kernel, AppArmor, Seccomp Hardening for Servers and Containers: PCI DSS Compliance, Automated Hardening and OpenSCAP Audits on RHEL, Ubuntu and Container Workloads

Linux Shell Scripting and Command Line: From Basics to Mastery

Mastering Debian Linux: Power User and Sysadmin Techniques