Perhaps you should try some spelling variations:
research profession » research professional, research progression, research professionals
research professor » research progresson, research process, research processes
research problems » research progress, research process, research program

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