Well I would try by doing a literature search on one of the subject or publisher databases (or even google scholar) - or are you asking us to do that for you?
And then when you have done the literature search you can read the literature, identify the gaps and then come up with YOUR research question. We all (well those of us who are mid way through) have our own research topics; similarly you need to come up with your own. Or do you want us to do that for you as well?
In fact why don't I do a literature search, come up with a research question, write a proposal, undertake some research, write it up in a thesis, sit a viva, make the ammendments for you? Oh because that would make it MY PhD and not YOURS.