Classic Shell Scripting
Unix Shell Programming (3rd Edition)
Murach's Oracle SQL and PL/SQL for Developers, 2nd Edition
UNIX and Linux System Administration Handbook, 4th Edition
grep Pocket Reference: A Quick Pocket Reference for a Utility Every Unix User Needs (Pocket Reference (O'Reilly))
Wicked Cool Shell Scripts, 2nd Edition: 101 Scripts for Linux, OS X, and UNIX Systems
Linux Pocket Guide: Essential Commands
Linux Bible
A Practical Guide to the UNIX System (3rd Edition)
sed & awk