Perhaps you should try some spelling variations:
research professor » research profession, research processes, research prozess
research problems » research progress, research project, research program
research process » research progress, research projects, research project

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