Rootkits and Bootkits
Alex Matrosov, Eugene Radionov, Sergey Bratus
The Linux Command Line, 2nd Edition
William Shotts
AD&D 5th Edition - Wayfinder's Guide to Eberron (v3)
Wizards of the Coast
Linux System Programming
Robert Love
Unix Power Tools
Shelley Powers
Linux Pocket Guide
Daniel J. Barrett
Linux in a Nutshell
Ellen Siever & Stephen Figgins & Robert Love & Arnold Robbins
Linux Device Drivers
Jonathan Corbet & Alessandro Rubini & Greg Kroah-Hartman
grep Pocket Reference
John Bambenek & Agnieszka Klus
Effective Awk Programming
Arnold Robbins
Cybersecurity Ops with bash
Paul Troncone & Carl Albing Ph.D.
Classic Shell Scripting
Arnold Robbins & Nelson H. F. Beebe
Bash Cookbook
Carl Albing & JP Vossen
Linux Basics for Hackers
OccupyTheWeb