Linux System Security: The Administrator's Guide to Open Source, Mann and Mitchell, Prentice Hall, ISBN 0-13015-807-0.
2000 Siyan and Hare, Internet Firewalls and Network Security, New Riders Publishing.
“Tripwire Opens Up Best of Breed' Security Tool”, by David Penn, Linux Journal web site, http://www.linuxjournal.com/articles/business/034.html.
“Post-Installation Security Procedures”, Eddie Harari, Linux Journal, December 1999. Available on-line at www.linuxjournal.com/article/3554.