Use the publications that are really important for your literature review (key papers) as a starting point for a snowball search. It's not necessary to do this for every article that you find.
Often a researcher will publish more articles on a specific topic or perform research on related topics. You can for instance:
The author will also have done a literature review and refer to relevant research. Check the reference list / literature / bibliography at the end of the key paper.
This is backward snowballing, you will only find older publications (compared to the key paper).
You can search for articles that refer to a key publication using the "cited by" method. You can for instance look up the article on Google Scholar and click the "cited by" button. This option is also available in Web of Science and Scopus.
This is forward snowballing, you will only find more recent publications (compared to the key paper).
