Perhaps you should try some spelling variations:
research progression » research progress, research progresses, research professional
research regression » research depression, research session, research regulation
research professor » research profession, research process, research processes

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((research professor) OR (((research progression) OR (research regression)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((research professor) or (((research progression) OR (research regression))))".
• Adding a wildcard symbol may retrieve word variants: ((research professor) or (((research progression) OR (research regression))))*.