Perhaps you should try some spelling variations:
research professional » researching professional, resources professional, health professional
research profession » research progression, research professionals, research progressions
research professor » research process, research processes, research prozess

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 profession) OR (research professional)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((research professor) or (((research profession) OR (research professional))))".
• Adding a wildcard symbol may retrieve word variants: ((research professor) or (((research profession) OR (research professional))))*.