Indeed, that is unfair Jean since so many of the publications are not available for free reading (your direct reference is AU $25 just to read, the excerpt displayed in my Google scan did not even include the information of interest in the Abstract). Much of the content on Wikipedia does give references for content like this and they work hard at marking information that is not officially referenced (especially for the sciences). If students are not allowed to actually site Wikipedia, at least mention that it provides a place to find actual material sources for a topic. For everyday, quick reference use (often leading to rabbit trailing), I find it indispensable and use it for definitions almost daily.
