Black Swan

I think for my research writing paper I want to do an analysis on the movie Black Swan. I think this movie will be interesting to research because in the movie there are many scenes where it's hard to tell what's really happening and what's imagined. So I'd like to take a look at that and see if we can figure out what really happened. I found some really cool internet articles that I think I might use:
http://abcnews.go.com/Health/Movies/black-swan-psychiatrists-diagnose-natalie-portmans-portrayal-psychosis/story?id=12436873

http://www.oddfilms.com/blog/movie-recommendations/black-swan-movie-interpretation/

http://vigilantcitizen.com/?p=6223

But I do need to be careful on what kinds of sources  I use. I was also thinking of watching the real ballet Swan Lake so I can see the original story the film is based on. I'm sure there are tons of videos out there about it and will be easy to find. The only thing I'm worried about for this paper is finding enough sources to use and making sure they're reliable. But this movie was so good and really interesting and I would really like to write about it!