If your topic of interest is emerging (e.g. COVID-19 health disparities), working papers, preprints, and other non-traditional sources beyond formal publications may be relevant. Check with your instructor to see whether or not they are permitted as sources for an assignment.
Working Paper: preliminary, not published in journals or formal publications
Preprints: the final draft of a paper before formatting is added for publishing in a journal, sometimes found in open access institutional repositories
Google Scholar is a good place to search to find both traditional and non-traditional scholarly publications:
