> One thing about citing or making use of Wikipedia contents: I find that I
> need to give a date for the "version" of the article that I am referring to.
> I have found some articles of interest to drastically change in its contents
> in less than a year.
Like most other Web 2.0 platforms, the MediaWiki software offers permanent links to article versions. If you are using the default skin, under the toolbox heading to the left of the screen you will find a bookmarkable permalink. The current version of en:Closed_class, for example, can be quoted as http://en.wikipedia.org/w/index.php?title=Closed_class&oldid=458419549. You can also view the history and link to any specific prior version.