The 5 AM Club
Robin Sharma
Practical Discrete Mathematics
Ryan T. White & Archana Tikayat Ray
Practical Linux System Administration
Kenneth Hess
Practical PHP and MySQL Website Databases
Adrian W. West
C# 8.0 Pocket Reference
Joseph Albahari & Ben Albahari
Java Pocket Guide
Robert Liguori & Patricia Liguori
Bash Pocket Reference
Arnold Robbins
Python Pocket Reference
Mark Lutz
Windows PowerShell Pocket Reference
Lee Holmes
SQL Pocket Guide
Jonathan Gennick
C++ Pocket Reference
Kyle Loudon
Regular Expression Pocket Reference
Tony Stubblebine
C Pocket Reference
Peter Prinz & Ulla Kirch-Prinz
sed & awk Pocket Reference