Hi burla009,
I assume you are talking about a master's dissertation. Normally, the word count is limited somewhere between 10 to 15.000 words, depending on the university and the course. In that sense, you will only have to include studies that they are more relevant to the aim of the dissertation. It would be best, if you can compare your findings with the literature in the discussion. In that sense, ideally your literature review should complement the overall argument of your dissertation.
Hope this helps