Forum:Informational/Analytical Books?

I'm writing my final research paper for school, science related, and thought I would make an effort to choose a subject that is interesting to me. Naturally, I chose Doctor Who. Only problem is, I've been overwhelmed with the surplus of Doctor Who related books and can't find a quality nonfiction book about the show as a whole.

If anyone could tell me of a more informational or analytical book about the series, preferably one that talks a bit about the underlying social commentary and the effects the show has on science fiction culture, that would be much appreciated.