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 <\#145>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 http://www.linuxjournal.com/lj-issues/issue68/3554.html.