grep Pocket Reference
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Linux in a Nutshell
Ellen Siever & Stephen Figgins & Robert Love & Arnold Robbins
Penetration Testing: A Hands-On Introduction to Hacking
Gorgia Weidman
Quick Start Guide
John Schember
Learning the Vi and Vim Editors
Arnold Robbins & Elbert Hannah
Docker: Up & Running
Sean P. Kane & Karl Matthias