Using Google Scholar
1) Copy/Paste the title of an article you found and check the Cited By options for
additional articles (Save any PDFs of new article you find to Google Drive
Folder / Add citations to your Reference page).
2) From one of your articles, find an article from one of the reference pages. If
useful, save any PDFs of new article you find to Google Drive Folder / Add
citations to your Reference page
3) If time, search Google Scholar for additional articles.