1. Absolute OpenBSD ISBN-10: 1593274769 ISBN-13: 978-1-59327-476-4
  2. Book of PF ISBN-10: 1-59327-589-7 ISBN-13: 978-1-59327-589-1
  3. Httpd and Relayd Mastery ISBN-10: 1-54675-206-4 ISBN-13: 978-1-54675-206-6
  4. SSH Mastery ISBN-10: 1642350028 ISBN-13: 978-1642350029
 Secure Architectures with OpenBSD
    by Brandon Palmer, Jose Nazario. 
    ISBN 03-21193-66-0 
    April 2004, 520 pp.

 The Design and Implementation of the 4.4BSD Operating System
    by Marshal Kirk McKusick, Keith Bostic, Michael J. Karels, John S. Quarterman 
    ISBN-10: 0132317923 
    ISBN-13: 978-0132317924 

Advanced Programming in the Unix Environment (3rd Edition)

    by W. Richard Stevens, Stephen A. Rago 

The C Programming Language

    by Brian W. Kernighan and Dennis M. Ritchie 

DNSSEC Mastery

    by Michael W. Lucas 
    ISBN-13: 978-1484924471 
    ISBN-10: 1484924479 
    May 2013, 130 pp. 
    Securing the Domain Name System with BIND 

TCP/IP Illustrated, Volume 1

    by W. Richard Stevens 

IPsec: The New Security Standard for the Internet, Intranets and Virtual Private Networks

    by Naganand Doraswamy and Dan Harkins 

Computer Networks

    by Andy Tanenbaum 


    by Paul Albitz and Cricket Liu 


    by Ted Lemon and Ralph E. Droms