The Official SuSE Proxy-Suite Home Page: www.suse.de/en/whitepapers/proxy_suite
“File Transfer Protocol”, the RFC That Specifies How FTP Works: ftp.isi.edu/in-notes/rfc959.txt
“History of Firewall Technologies” by Rik Farrow and Richard Power: www.spirit.com/Network/net0597.txt
Official Home Page for Building Secure Servers with Linux by Mick Bauer: www.oreilly.com/catalog/bssrvrlnx