Have you checked if your uni has a set structure for the thesis? Mine does, and the reference list has to be at the end. But, as with others, I think it would be unusual for the references to be anywhere other than the end. Think of the examiner, they're not reading the thesis as a set of single essays, they're reading it as one body of work. I know that when I read other people's work, I often go straight to the reference list early on - to see if what they're citing highlights anything interesting for me. It would be super annoying to have to find multiple sections of references to do that....