OpenBSDs web http://www.openbsd.org/
OpenBSDs FAQ, http://www.openbsd.org/faq/index.html
PF User Guide http://www.openbsd.org/faq/pf/index.html
Daniel Hartmeiers PF-sider, http://www.benzedrine.cx/pf.html
Daniel Hartmeier: Design and Performance of the OpenBSD Stateful Packet Filter (pf), http://www.benzedrine.cx/pf-paper.html (presentert på Usenix 2002)
Nate Underwood: HOWTO: Transparent Packet Filtering with OpenBSD, http://ezine.daemonnews.org/200207/transpfobsd.html
Randal L. Schwartz: Monitoring Net Traffic with OpenBSD's Packet Filter, http://www.samag.com/documents/s=9053/sam0403j/0403j.htm
Unix.se: Brandvägg med OpenBSD, http://unix.se/Brandv%E4gg_med_OpenBSD
Randal L. Schwartz: Blog for Thu, Jan 29, 2004, http://use.perl.org/~merlyn/journal/17094
RFC 1631, "The IP Network Address Translator (NAT)", mai 1994 http://www.ietf.org/rfc/rfc1631.txt?number=1631
RFC 1918, "Address Allocation for Private Internets", februar 1996 http://www.ietf.org/rfc/rfc1918.txt?number=1918
Hjemmeside for PF på FreeBSD, http://pf4freebsd.love2party.net/
Peter Postmas PF på NetBSD-sider, http://nedbsd.nl/~ppostma/pf/