NGINX High Performance
Rahul Sharma
The GNU Make Book
John Graham-Cumming
SQL Injection Attacks and Defense
Justin Clarke & Kevvie Fowler & Erlend Oftedal & Rodrigo Marcos Alvarez & Dave Hartley & Alexander Kornbrust & Gary O'Leary-Steele & Alberto Revelli & Sumit Siddharth & Marco Slaviero
Defensive Security Handbook: Best Practices for Securing Infrastructure
Lee Brotherston & Amanda Berlin
RT Essentials
Richard Foley
Time Management for System Administrators
Thomas A. Limoncelli