Is each fact referenced with an appropriate, reliable reference? - No, there are a lot of missing in text citations. These parts either need to be removed or properly referenced.
Where does the information come from? Are these neutral sources? If biased, is that bias noted? - The information is coming from newspaper sources, such as the Toronto Star, and the Hamilton Spectator, as well as from Youtube and greatesthockeylegends.com. These sources are neutral, and did not show any forms of bias.
Are there viewpoints that are overrepresented, or underrepresented? - Yes, at the end they briefly touch upon Stan Jonathan's criminal charges; however, it is very underrepresented in the article.