Citations from web pages:
Authors may sometimes wish to cite information available from the
internet in similar ways to the citation of published literature. In
using this option, authors are asked to ensure that:
fully authenticated addresses are included in the reference list, along
with titles, years and authors of the sources being cited, and the most
recent date the site was accessed; the sites or information sources have
sufficient longevity and ease of access for others to follow up the
citation; the information is of a scientific quality at least equal to
that of peer-reviewed information available in learned scientific
journals; hard literature sources are used in preference where they are
available. It is likely that official web sites from organisations such
as learned societies, government bodies or reputable NGOs will most
often satisfy quality criteria.