I am doing my Phd study. My supervisor attended a new conference and after that, she asked me to update my literature review based on new works mentioned in this conference. I looked at all the presented works which are relative to my work, however, I just found the abstracts of these works. I contacted the authors and they told me that they did not publish their works and hence cannot share them with me. I tried to do what my supervisor asked me to do but I really cannot read the entire works and hence cannot understand what the authors did. So, what I have to do in this case? Do I need to just mention the abstract (which is really not enough to understand the methodology of the work)? Any help please?
Unless your completion is immanent, you shouldn't have a problem. Include the new work in the lit review for now, but monitor the situation. Hopefully the conference proceedings will appear and contain the papers and you can make adjustments as needed.
If the timing is not as I suggest here, then just explore this with your advisor and follow whatever advice you get. For the purposes of your dissertation, all should be well. If you later publish the work you may need to adjust some references, of course, but you might need to do that in any case if you learn more in the interim.
Tell your supervisor and ask if she'll email the authors (ideally addressing emails to someone she met at the conference or already knows). She might be more successful than you, because she is more senior and because she was there (and because she knows them already).