referencing articles from WWW

[J Loh]

Hi! I'm a student in science who is about to start writing a
thesis report. One question I have is...how do I reference 
an article I found on the www ? 

Is there a international way of doing this that is acceptable say
in a journal?

Keeping in mind a reference is placed to enable other people to find
the information....works well for journals, books etc. HOw about WWW ?
The way i see it...the web address might work for awhile and then if the
authour decided to erase or overwrite etc...there goes the article.

Is there a international accepted protocol or way of referencing
web articles yet?

Any help would be greatly appreciated.
Thanks,

JImmy Loh