VIEGA, J., MESSIER M., CHANDRA P. - Network Security with OpenSSL, 2002, 978-0596002701.
COLLIER,M.,ENDLER,D. - Hacking Exposed Unified Communications & VoIP Security Secrets & Solutions, Second Edition, 2013, 978-0071798761.
RASH, M.- Linux Firewalls: Attack Detection and Response with iptables, 2007, 978-1593271411.