Mastering Linux Security and Hardening
Donald Tevault
The Developing Person Through the Life Span
Kathleen Berger
Linux® All-in-One For Dummies®, 6th Edition
Emmett Dulaney
Red Hat Enterprise Linux 7: Desktops and Administration
Richard Petersen
Unauthorised Access
Wil Allsopp
CCNA Certification Practice Tests
Jon Buhagiar
Cryptography Engineering
Niels Ferguson & Bruce Schneier & Tadayoshi Kohno