There are several different types of literature available and you will probably draw on all of them. The ones you will refer to in your literature review fall into two main areas.
This is the work done by specialists in the field. Their writings will become your secondary sources on which you will draw in your own research. These are usually published, either in printed or e-book format. The main types are monographs—books describing a particular piece of research in detail (e.g., a PhD thesis)—and articles in academic journals.
To search for sources, please visit the library's homepage.