@misc{ postgresql,
author = "PostgreSQL Global Development Group",
title = "PostgreSQL: The world's most advanced
open source database"
howpublished = "http://www.postgresql.org/",
note = "Accessed: 7 March 2008", }
which produces
PostgreSQL Global Development Group.
PostgreSQL: The world's most advanced open source database.
http://www.postgresql.org/.
Accessed: 7 March 2008.