Dissertation: Literature Review

Now for my concept map that represents my literature review. This is how it's shaping up, and hopefully I won't have to add too much to it (I'm fine with taking stuff out). I've been struggling with it and getting contradictory advice, which I've come to understand is common, and which boils down to one question: Is it preferable, in a dissertation, to enter a specific conversation in one field of study, or to get a broader sampling of books and articles representing multiple disciplinary perspectives on your general topic/object of study, even though you run the risk of overlooking some important work? I'm hoping to be able to do the former, as you can see on the concept map. I want this thing to be wieldy. (This image links to a larger one.)

But if there are problems, I need to know, and I'm always grateful for feedback, so please leave it here or email me.